The emergence of novel phytopathogens and the accelerated spread of plant diseases to new regions, driven by global climate change, constitute significant threats to agricultural resources. Rice, a major tropical staple crucial for global food security, possesses six transcription factor superfamilies—AP2/ERF, bHLH, bZIP, MYB, NAC, and WRKY—that function in innate immunity against pathogens. We review their biological functions and regulatory mechanisms in rice immunity.

Viruses are significant pathogens causing severe plant infections and crop losses globally. The resistance mechanisms of rice to viral diseases, particularly Southern rice black-streaked dwarf virus (SRBSDV), remain poorly understood. In this study, we assessed SRBSDV susceptibility in 20 Xian/indica (XI) and 20 Geng/japonica (GJ) rice varieties. XI-1B accessions in the Xian subgroup displayed higher resistance than GJ accessions. Comparative transcriptome analysis revealed changes in processes like oxido-reductase activity, jasmonic acid (JA) metabolism, and stress response. JA sensitivity assays further linked antiviral defense to the JA pathway. These findings highlight a JA-mediated resistance mechanism in rice and offer insights for breeding SRBSDV-resistant varieties.

An accurate assessment of host and pathogen gene expression during infection is critical for understanding the molecular aspects of host-pathogen interactions. Often, pathogen-derived transcripts are difficult to ascertain at early infection stages owing to the unfavourable transcript representation compared to the host genes. In this study, we compare two sequencing techniques, RNAseq and enrichment sequencing (RenSeq and PenSeq) of cDNA, to investigate gene expression patterns in the doubled monoploid potato (DM) infected with the late blight pathogen Phytophthora infestans. Our results reveal distinct advantages of cDNA RenSeq and PenSeq over traditional RNAseq in terms of target gene representation and transcriptional quantification at early infection stages. Throughout the infection time course, cDNA enrichment sequencing enables transcriptomic analyses for more targeted host and pathogen genes. For highly expressed genes that were sampled in parallel by both cDNA enrichment and RNAseq, a high level of concordance in expression profiles is observed, indicative of at least semi-quantitative gene expression representation following enrichment.

Fusarium ear rot (FER), caused by Fusarium verticillioides, is a destructive fungal disease of maize. FER resistance is a complex, quantitatively inherited trait controlled by multiple minor-effect genes. In this study, we employed two recombinant inbred line (RIL) populations with the common resistant parental line CML304 to identify FER-resistance loci. Initial QTL analysis identified 23 FER-resistance QTL, each explaining 5.21%-30.51% of the total phenotypic variation. Notably, one major QTL, qRfv2, on chromosome 2 was repeatedly detected, accounting for 11.92%-30.51% of the total phenotypic variation. qRfv2 was fine mapped to an interval of 1.01 Mb, flanked by the markers IDP8 and IDP10. qRfv2 is a semi-dominant resistance gene that could reduce the disease severity index (DSI) by 12.4%-20%, suggesting its potential for enhancing FER resistance in maize. Transcriptome analysis showed that 22 of the 28 annotated functional genes in the qRfv2 region displayed differential expression between parental lines in response to FER. One of the candidate genes, ZmLOX6, was validated to presumably provide a positive effect on FER resistance. Our study provides a basis for the potential cloning and application of FER resistance genes in maize breeding.

Pythium stalk rot (PSR) is a destructive disease of maize, severely affecting yield and grain quality. The identification of quantitative trait loci (QTL) or genes for resistance to PSR forms the basis of disease-resistant hybrids breeding. In this study, a major QTL, Resistance to Pythium stalk rot 1 (RPSR1), was identified from a set of recombinant inbred lines derived from MS71 and POP. Using a recombinant progeny testing strategy, RPSR1 was fine-mapped in a 472 kb interval. Through candidate gene expression, gene knock-down and knock-out studies, a leucine-rich repeat receptor-like kinase gene, PEP RECEPTOR 2 (ZmPEPR2), was assigned as a PSR resistance gene. These results provide insights into the genetic architecture of resistance to PSR in maize, which should facilitate breeding maize for resistance to stalk rot.

Powdery mildew negatively impacts wheat yield and quality. Emmer wheat (Triticum dicoccum), an ancestral species of common wheat, is a gene donor for wheat improvement. Cultivated emmer accession H1-707 exhibited all-stage resistance to powdery mildew over consecutive years. Genetic analysis of H1-707 at the seedling stage revealed a dominant monogenic inheritance pattern, and the underlying gene was designated Pm71. By employing bulked segregant exome sequencing (BSE-Seq) and using 2000 F_2:3 families, Pm71 was fine mapped to a 336-kb interval on chromosome arm 6AS by referencing to the durum cv. Svevo RefSeq 1.0. Collinearity analysis revealed high homology in the candidate interval between Svevo and six Triticum species. Among six high-confidence genes annotated within this interval, TRITD6Av1G005050 encoding a GDSL esterase/lipase was identified as a key candidate for Pm71.

The NAC (NAM, ATAF1/2, and CUC2) is a defense-associated transcription factor (TF) family that positively regulates defense responses to pathogen infection. TaNAC069 positively regulates resistance in wheat to Puccinia triticina (Pt). However, the molecular mechanism of its interaction with a Pt effector is not clear. We found that Pt effector Pt-1234 interacts with TaNAC069 to subvert host immunity during Pt infection. Quantitative real-time PCR analysis showed that expression of Pt-1234 was significantly up-regulated during the early stage of Pt infection. Protein-mediated cell death assays in wheat showed that the Pt-1234 protein was unable to induce cell death in wheat near-isogenic lines carrying different leaf rust resistance genes, whereas it suppressed BAX-induced cell death in leaves of Nicotiana benthamiana. Silencing of Pt-1234 by host-induced gene silencing (HIGS) significantly reduced the virulence of Pt in the susceptible wheat variety Thatcher. The C subdomain of TaNAC069 was responsible for its interaction with Pt-1234, and the E subdomain was required for TaNAC069-mediated defense responses to Pt in planta. These findings indicate that Pt utilizes Pt-1234 to interact with wheat transcription factor TaNAC069 through its C subdomain, thereby modulating wheat immunity.

The RING-type E3 ligase OsBBI1 regulates rice resistance against Magnaporthe oryzae through modifying cell wall defenses. In this study, we report the function of an OsBBI1 substrate, eukaryotic translation initiation factor OseIF5A4, in rice immunity. OsBBI1 interacts with OseIF5A4 and other four members of the OseIF5A family. The RING domain in OsBBI1 and the eIF-5a domain in OseIF5A4 are critical for the OsBBI1-OseIF5A4 interaction. OsBBI1 ubiquitinates OseIF5A4 and mediates its degradation in vitro and in vivo. Moreover, the expression of OseIF5A4 was upregulated during early stage of compatible interaction but downregulated in incompatible interaction between rice and M. oryzae. Knockout of OseIF5A4 enhances rice immunity against M. oryzae and Xanthomonas oryzae pv. oryzae, boosts pattern-triggered immune responses, and strengthens pathogen-induced defense responses (e.g., expression of defense genes, accumulation of reactive oxygen species and reinforcement of cell wall). However, overexpression of OseIF5A4 attenuates rice immunity and immune responses. These results demonstrate that OseIF5A4, a substrate of the immunity-associated E3 ligase OsBBI1, negatively regulates rice immunity against M. oryzae and X. oryzae pv. oryzae through modulating pathogen-induced defense responses, highlighting the importance of the protein translational machinery in rice immunity.

Rice sheath blight (RSB) is a major destructive disease impeding rice production. Identifying key germplasm resources with increased resistance remains a challenge. However, the mechanisms underlying disease resistance are not yet fully understood. Cytochrome P450 monooxygenases (CYP450s) serve biosynthesis and metabolic detoxification functions in plants, but there is limited information about their role in the response induced by RSB. This study demonstrated that CYT02 belongs to the CYP73A100 subfamily and is a typical member of the CYP450s. Overexpression (OE) in rice of the cytochrome P450 monooxygenase cyt02 conferred increased resistance to RSB and increased vegetative tillering. Cyt02 may increase RSB resistance by regulating plant hormone synthesis, regulate reactive oxygen species (ROS) by coordinating the activity of antioxidant enzymes, and initiate phytoalexin synthesis in response to fungal infection. These research findings have laid a foundation for a deeper understanding of the function of cyt02 and offered a potential target gene for breeding rice varieties resistant to sheath blight.

Asian rice comprises two major subspecies: Xian (X) and Geng (G), and the diverged resistance genes (R) have provided a foundation for breeding improved cultivars to control rice blast disease. After conducting two-phase allele mining using six updated FNP marker systems, the functional haplotypes at Pit, Pib, and Pi63 strictly diverged into the X-populations and were defined as X-R loci, while those at Pi54, Pi37, and Pi36 into the G-populations as G-R loci. The genic diversity at the three X-R loci (16 alleles) was twofold higher than that at the three G-R loci (8 alleles), and the allelic diversity in the Southern region (21 alleles) was nearly double that in the Northeastern region (11 alleles). Both observations reflect a significant difference in genetic diversity between X- and G-populations, and indicate that the effective R-genes mainly originated from X-subspecies. Based on the allelic structures characterized by a set of 10 parameters, 8 and 16 alleles were respectively recognized as favorable and promising ones for the regional breeding programs. The genotypic structures of the two regional populations were almost different, indicating that the diverged alleles have been further assembled into two series of regional genotypes through long-term breeding programs, despite the presence of one-third of region-common alleles. The genotypic diversity in the Southern region (55 genotypes) was nearly twice as high as that in the Northeastern region (28), which perfectly reflects the aforementioned differences in both genic and allelic diversities. After analyzing the genotypic structures using a set of 13 parameters, 4 and 23 genotypes, respectively, can be recommended as the favorable and promising ones for the regional breeding programs. The case study serves as a concrete sample of how to identify the favorable and promising alleles and genotypes, and beneficial parents based their comprehensive population structures for gene-designed breeding.

Bacterial blight (BB), caused by Xanthomonas oryzae pathovar oryzae (Xoo), poses a significant threat to rice production, particularly in Asia and West Africa. Breeding resistance against BB in elite rice varieties is crucial to advancing rice breeding program and supporting smallholder farmers. Transcription Activator-Like effectors (TALes) are key virulence factors in Xoo, with some targeting the susceptibility (S) genes such as the sugar transporter SWEET genes in rice. Among these, SWEET14 is an important S gene, with its promoter bound by the TALe TalC which exists across all sequenced African Xoo isolates. In the present study, we utilized CRISPR/Cas9-based cytidine and adenine base editors to alter the effector binding element (EBE) of TalC in the promoter of SWEET14 in rice cultivars Kitaake, IR24, and Zhonghua 11. Mutations with C to T changes in EBE led to reduced SWEET14 induction by TalC-containing Xoo strains, resulting in resistance to African Xoo isolates reliant on TalC for virulence. Conversely, A to G changes retained SWEET14 inducibility and susceptibility to Xoo in edited lines. Importantly, no off-target mutations were detected at predicted sites, and the edited lines exhibited no obvious defects in major agronomic traits in Kitaake. These results underscore the effectiveness of base editing systems for both molecular biology research and crop improvement endeavors.

Wild peanut (Arachis) species are promising sources of disease resistance for improving peanut cultivars. The objective of this study was to assess cross-compatibility among cultivated and wild peanuts in crosses between eight peanut cultivars and 27 wild species carrying the A, B, E, Ex, F, K, P, and H genomes. Embryo culture and chromosome doubling led to polyploids representing hybrids between cultivated peanut and A. stenosperma, A. macedoi, A. duranensis, A. villosa, and A. diogoi. The first two showed greater resistance to bacterial wilt than their cultivated parents. DNA markers were developed for verifying the hybrids and for identifying translocation or introgression lines with alien chromosome fragments.

Pre-harvest sprouting (PHS) describes the germination of physiologically mature grains in spikes prior to harvest in cereal crops. PHS could seriously decrease grain yield and quality, which makes it a major constraint to cereal production worldwide. A number of PHS-associated genes in cereals have been reported; however, the molecular mechanisms underlying PHS remain largely elusive. Here, we report a CRISPR-Cas9 mutant with severe PHS in a paddy field. The mutated gene OsMFT2 encodes a phosphatidylethanolamine-binding protein (PEBP). Intriguingly, the OsMFT1, in the same PEBP family, had the opposite effect in controlling rice PHS as does OsMFT2. Germination tests of seeds of chimeric protein-expressing plants revealed that the fourth exon conferred the antagonistic activity of OsMFT1 and OsMFT2 in rice PHS. Additionally, two lines of these plants showed elevated grain numbers per panicle, implying that chimeric protein has potential to significantly increase yield. Moreover, transcriptome analysis and genetic studies indicated that OsMFT1 and OsMFT2 performed opposing functions in rice PHS owing to three co-regulated genes that being contrastingly affected by OsMFT1 and OsMFT2. Overall, it seemed that the proper combination of PEBP family members could obtain optimal PHS resistance and high yield.

Transcription factors (TFs) play key roles in the regulatory network of leaf senescence. However, many nodes in this network remain unclear. To elucidate the mechanism of leaf senescence mediated by a rice TF, WRKY10, the expression of multiple senescence-related genes and physiological phenotypes were monitored in WRKY10- and VQ MOTIF-CONTAINING PROTEIN8 (VQ8)-overexpressing plants and the wrky10 and vq8 mutants. Our results showed that WRKY10 positively regulates abscisic acid (ABA)- and dark-induced senescence (DIS) by directly regulating the expression of multiple senescence-related genes. The VQ8 protein, a repressor of WRKY10, negatively regulates WRKY10-mediated DIS. The WRKY10-VQ8 module fine-tunes the progression of DIS. ABA, methyl jasmonate, and H₂O₂ accelerate WRKY10-mediated DIS, whereas ammonium nitrate and dithiothreitol delay WRKY10-mediated DIS. Further analysis revealed that WRKY10 and VQ8 interact with ABA RESPONSIVE ELEMENT BINDING FACTOR1 (ABF1) or ABF2. VQ8 represses the transcriptional activity of ABF1 and ABF2. Overexpression of ABF1 or ABF2 accelerates ABA- and dark-induced senescence and H₂O₂ accumulation in N. benthamiana leaves, and WRKY10 and VQ8 can inhibit either ABF1- or ABF2-induced cell necrosis. Taken together, WRKY10 integrates multiple senescence signals to establish an orderly progression of leaf senescence. The VQ8 protein acts as a brake on WRKY10-induced senescence and ABF1/2-induced cell death, preventing uncontrolled cell death.

Rice grain size is a primary characteristic essential for artificial domestication and breeding, governed by grain length, width, and thickness. In this study, we cloned Grain Size 10 (GS10), a novel gene via map-based cloning. Biochemical, molecular, and genetic studies were performed to elucidate the GS10 involved grain size mechanism in rice. Mutant of GS10 lead to reduced grain size due to alterations in cell expansion. Additionally, GS10 is responsible for the formation of notched-belly grains, especially in smaller grain varieties possessing loss-function mutations. Overexpression of GS10 in Nipponbare results in increasing grain length, grain weight and improve the appearance quality of rice. GS10 encodes conserved protein with uncharacterized function. Furthermore, GS10 regulates the grain size by interacting OsBRICK1, a subunit of the WAVE complex that governs actin nucleation and affects the assembly of microfilaments in rice. Together, our study demonstrates that, GS10 positively regulates the grain length and grain weight, which is beneficial for further improvements in yield characteristics.

Meiosis, a critical process for sexual reproduction, requires precise regulation to ensure the correct progression of meiotic stages. In yeast and animals, errors in meiotic recombination and homologous chromosomes synapsis bring a surveillance mechanism named pachytene checkpoint to prevent pachytene exit. However, most plant mutants with defects in meiotic prophase I continue cell cycle progression, which hindered the characterization of factors controlling the prophase I to metaphase I transition. Here, we characterized a male-sterile mutant in maize, prolonged prophase1 (pp1), which exhibited pachytene and diakinesis arrest in male meiosis, and abnormal chromatin condensation. Using map-based cloning, the PP1 gene was isolated as a PHD family transcription factor, and its transcripts of PP1 were preferentially accumulated in tapetum and male germline cells during microsporogenesis. Transcriptomic analysis of the pp1 mutant revealed downregulation of genes associated with chromatin assembly, cell cycle, and male meiosis, correlating with observed meiotic arrest and chromatin condensation defects. These findings highlight the role of PP1 in maize microsporogenesis, and providing more insights into the mechanisms regulating the meiotic progression in maize.

Arogenate dehydratase (ADT) catalyzes the final step in phenylalanine synthesis and is crucial for plant development and metabolism. Previously, we demonstrated that the ADT/prephenate dehydratase ZmADT2 is essential for maize resistance to Ustilago maydis and for overall plant development. In this study, we explored the role of ZmADT2 in maize kernel development. The mmsu mutant, a dysfunctional ZmADT2 variant, exhibits delayed embryo and endosperm development, along with deficiencies in carbohydrate and protein storage. Transcriptome analysis revealed differential expression of many kernel compartment-specific genes between mmsu and wild-type (WT) kernels, with impaired nutrient accumulation and auxin signaling pathway in the mmsu endosperm. Compared to WT, ZmADT2 mutation led to reduced auxin levels and smaller endosperm cell size. Exogenous auxin rescued the small kernel phenotype of mmsu. Additionally, auxin distribution was reduced in the basal endosperm transfer layer (BETL), causing defects in its development and function, including reduced transfer cell elongation, cell wall ingrowth and nutrient uptake. These findings suggest that ZmADT2 mediated mediates an auxin signaling pathway that is essential for maize kernel development.

Phosphorylation is one of the major posttranslational modifications to control plant growth and development. Opaque2 (O2) represents a central hub for endosperm filling, which largely determines seed yield and nutrient storage in maize. However, it still remains unclear how O2 phosphorylation orchestrates endosperm filling and nutrient quality. Here, we systematically identified the phosphorylation sites of O2 during endosperm filling. A total of 18 phosphorylation sites were found in O2 and five sites were identified to apparently modulate its subcellular localization and transactivation capacity. In addition, a conserved protein kinase CK1 was confirmed to interact with and phosphorylate O2 at the residue Threonine (T)202 to promote O2-mediated transactivation and protein stability. Overexpression of CK1 resulted in increased kernel size, 100-kernel weight and nutrient storage. Phosphorylation-mimic O2 seeds at T202 exhibited enhanced kernel dimension, test weight, vitreous endosperm area and nutrient accumulation, whereas the phosphorylation-deficient O2 seeds did not. Collectively, this study establishes a comprehensive phosphocode atlas of O2 during endosperm filling and highlights the importance of phosphorylation modification in O2 to precisely orchestrate maize yield and nutrient quality.

The high content of cyanogenic glycosides (CG) in cassava tubers affects food safety. CG are involved in the plant growth and development and protect cassava leaves from herbivorous predators. However, the regulatory mechanism of CG biosynthesis remains poorly understood. Here, yeast one-hybrid assays were performed using a mixed cDNA library of cassava tubers and leaves as prey and the promoter of MeCYP79D2 as bait. MeCYP79D2, a cytochrome P450 protein, is the rate-limiting enzyme for CG synthesis in cassava. From this information, a candidate regulator of MeCYP79D2 was selected and identified as transcription factor MePHD1.2. MePHD1.2, located in the nucleus and exhibiting an inhibitory transcription activity directly bound to an AT-rich motif in the promoter of MeCYP79D2. In cassava, the transcriptional activity of MeCYP79D2 was considerably enhanced in mephd1.2 mutant lines leading to increased linamarin and lotaustralin contents. Deletion of MePHD1.2 promoted the production of CGs in cassava and decreased transcription inhibition on MeCYP79D2, exposing a novel regulatory module governing biosynthesis of CGs.

Submergence can induce anaerobic stress on germinating seedlings in direct seeded rice paddy fields, limiting the practice of direct seeding. Longer coleoptiles improves the anaerobic tolerance of rice seedlings under submerged conditions. In a search for genes that could be beneficial for developing submergence-tolerant varieties 148 non-repetitive SNP loci were detected in on a genome-wide association study (GWAS) of coleoptile length (CL), coleoptile surface area (CSA), coleoptile volume (CV), and coleoptile diameter (CD) of 591 rice accessions subjected to 4 d of anaerobic conditions. Integration of GWAS results and gene expression data identified OsEE1, an early embryogenesis-specific enolase 1 gene associated with coleoptile length (CL) in rice grown in anaerobic conditions. Disruption of OsEE1 caused reduced CL in plants seeded under anaerobic conditions, whereas CL of OE-OsEE1 overexpression lines was significantly increased compared with the wild type. Functional analysis revealed that OsEE1 affects coleoptile length by modulating the glycolysis and tricarboxylic acid cycle pathways. Transcriptome sequencing of ko-osee1-1 knock out mutants highlighted enrichment in energy and carbohydrate metabolism, glycolysis, amino acid metabolism, and hormone signal transduction. Metabolite analysis indicated decreased levels of key metabolites in the tricarboxylic acid cycle and glycolysis pathways in ko-osee1-1 mutants compared to the wild type under anaerobic conditions. Overall, these findings shed light on the role of OsEE1 in determination coleoptile length of rice seedlings under anaerobic conditions.

Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents. Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor, the durum wheat LM, and selfing the pentaploid hybrids to the F₇ generation yielded mostly euploid tetraploids and a few hexaploids. Two special derivatives of tetraploid were isolated, including a 4D(4B) substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis. The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination. The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics (especially stress resistance) and quality functions and the functional study of the introduced chromosomes or fragments.

Dense cropping increases crop yield but intensifies resource competition, which reduces single plant yield and limits potential yield growth. Optimizing canopy spacing could enhance resource utilization, support crop morphological development and increase yield. Here, a three-year study was performed to verify the feasibility of adjusting row spacing to further enhance yield in densely planted soybeans. Of three row-spacing configurations (40-40, 20-40, and 20-60 cm) and two planting densities (normal 180,000 plants ha⁻¹ and high 270,000 plants ha⁻¹). The differences in canopy structure, plant morphological development, photosynthetic capacity and their impact on yield were analyzed. Row spacing configurations have a significant effect on canopy transmittance (CT). The 20-60 cm row spacing configuration increased CT and creates a favorable canopy light environment, in which plant height is reduced, while branching is promoted. This approach reduces plant competition, optimizes the developments of leaf area per plant, specific leaf area, leaf area development rate, leaf area duration and photosynthetic physiological indices (F_v/F_m, ETR, P_n). The significant increase of 11.9%-34.2% in canopy apparent photosynthesis (CAP) is attributed to the significant optimization of plant growth and photosynthetic physiology through CT, an important contributing factor to yield increases. The yield in the 20-60 cm treatment is 4.0% higher than in equidistant planting under normal planting density, but 5.9% under high density, primarily driven by CAP and pod number. These findings suggest that suitable row spacing configurations optimize the light environment for plants, promote source-sink transformation in soybeans, and further improve yield. In practice, a 20-60 cm row spacing configuration could be employed for high-density soybean planting to achieve a more substantial yield gain.

A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatio-temporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them, as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars. The results showed that the order of leaf senescence after silking in maize was lower leaf > upper leaf > ear leaf, leaf tip > middle > base. Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking, reducing CLH and PPH activities, thereby delaying the leaf senescence. These effects were more prominent in low-N-sensitive cultivar Xianyu 508 (XY508) than in low-N-tolerant cultivar Zhenghong 311 (ZH311), especially in the lower leaves and leaf tip. Under low N condition, leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508. This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311, which may be one of the important physiological bases of low nitrogen tolerant cultivars. Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.

Strip-till (ST), including straw mulching in the inter-row and localized fertilization in the intra-row, is a conservation tillage system for improving soil quality and crop growth. However, the yield advantage of maize under ST compared to conventional tillage (CT) remains unstable, and the strategies to increase maize yield under ST are unclear. This study aims to understand the physiological mechanism underlining maize yield formation under ST by comparing two maize cultivars, DKM753 and DK517, with contrasting yield performance in ST versus CT systems. Compared to CT, ST resulted in a 4.5% yield increase for DKM753 but a 5.6% decrease for DK517. These yield differences were primarily attributed to variations in grain number per ear (GN). During the rapid growth stage (V14-R3), i.e., two weeks before and after silking, DKM753 showed a 6.7% increase in maximum growth rate (V_max) and a 6.3% increase in average growth rate (V) under ST, whereas DK517 exhibited decline of 8.5% in V_max and 12.3% in V. Significant positive correlations are observed between V_max and V with GN under ST (R² = 0.79 and R² = 0.90, respectively). Enhanced dry matter accumulation in DKM753 under ST was attributed to increased leaf expansion rates, contributing to a larger photosynthate source. The straw mulching and localized nitrogen fertilization increased root-zone nitrogen availability at silking in ST compared to CT. DKM753 had a greater root system which made better use of the soil N and lead to an increased leaf nitrogen accumulation by 14.9% under ST. It is concluded that maize yield under the strip-till system is determined by grain number per ear, which can be increased by increasing nitrogen accumulation, plant growth, and ear development around silking stage. A sound root system can efficiently utilize soil nitrogen resources under the strip-till system, increasing plant nitrogen accumulation and thereby promoting plant growth.

Population size plays a crucial role in determining wheat yields. Altered carbohydrate accumulation resulting from increased competition between populations and individuals leads to poor-quality stems. The sowing date can mitigate competition in densely planted populations. However, the underlying mechanism by which it confers resistance to wheat lodging remains elusive. In this study, Zimai 28 (lodging-sensitive variety) and Shannong 28 (lodging-resistant variety) were used with three sowing treatments on October 22 (S1), October 28 (S2), and November 3 (S3). The sowing rate was adjusted to ensure adequate population size and consistency in the overwintering populations across sowing dates (300 plant m⁻² for S1, 375 plant m⁻² for S2, and 525 plant m⁻² for S3). The lodging resistance in winter wheat was increased by delayed sowing and increased sowing rate, which led to a reduction in tiller numbers and fostered primary stem development. A reduction in the overwinter cumulative temperature from 500 to 450 °C, coupled with an elevation in sowing rates from 300 to 375 plant m⁻² (transition from S1 to S2), corresponded with a notable increase in structural carbohydrates (lignin, cellulose, hemicellulose, and pectin) by 175.07 mg g⁻¹. Additionally, there was a moderate increase in non-structural carbohydrates, including soluble sugars and starch, by 15.54 mg g⁻¹. Delayed sowing and increased sowing rate elevated the precursor contents of lignin synthesis. Enhanced metabolic activity of related pathways ultimately increased dimer/trimer content. In summary, this study highlights the pivotal role of lignin metabolites and cross-linked structures in determining the stem stiffness breaking strength.

Drought is one of the most severe environmental stresses affecting soybean growth and development, especially in arid and semi-arid areas. The aim of this experiment is to evaluate the effect of regulated deficit irrigation during the vegetative stages on soybean plants and determine the amount irrigation water can be reduced without affecting the physiological parameters, the crop phenology, and the yield of the soybean crop. The field experiments were conducted during two irrigation crop seasons (2021 and 2022) in Louata, Morocco. The results showed that regulated deficit irrigation regimes during the vegetative stages was combined with high temperatures and low air humidities during the beginning of flowering and the pod filling stage during 2021 in comparison with 2022, especially for 25% CWR (crop water requirements). Regulated deficit irrigation regimes reduced the stomatal conductance by 46% and 52% respectively during the first and second growing seasons by limiting CO₂ intake for the Calvin cycle. The stomata closure increased the leaf temperature and affected the functioning of the photosynthetic apparatus by damaging the chlorophyll pigments and impairment of electron transport chains in chloroplasts. The transition from regulated deficit irrigation to 100% CWR at the beginning of flowering (R1) compensated for the photosynthetic loss, improved the growth and development of soybean plants and enhanced the yield and its components for 50% and 75% CWR. The adaptative mechanism such as the remobilization of the carbon reserved in the stems and leaves (vegetative tissues) to the grains improved the grain yield by 36.7% during 2021 and by 32.2% during 2022 and. This consequently improved the water use efficiency, the water productivity of soybean for 50% and 75% CWR and contributed to water saving with an average of 60 mm per growing season.

Aegilops speltoides, the closest ancestor of the wheat B subgenome, has been well studied genomically. However, the epigenetic landscape of Ae. speltoides and the effects of epigenetics on its growth and development remain poorly understood. Here, we present a comprehensive multi-omics atlas of leaves and roots in Ae. speltoides, encompassing transcriptome, DNA methylation, histone modifications, and small RNA profiling. Divergent DNA methylation levels were detected between leaves and roots, and were associated with differences in accumulated 24-nt siRNAs. DNA methylation changes in promoters and gene bodies showed strong connections with altered expression between leaves and roots. Transcriptional regulatory networks (TRN) reconstructed between leaves and roots were driven by tissue-specific TF families. DNA methylation and histone modification act together as switches that shape root and leaf morphogenesis by modulating the binding of tissue-specific TFs to their target genes. The TRNs in leaves and roots reshaped during wheat polyploidization were associated with alterations in epigenetic modifications. Collectively, these results not only shed light on the critical contribution of epigenetic regulation in the morphogenesis of leaves and roots in Ae. speltoides but also provide new insights for future investigations into the complex interplay of genetic and epigenetic factors in the developmental biology of common wheat.

Multiple phytohormones, including gibberellin (GA), abscisic acid (ABA), and indole-3-acetic acid (IAA), regulate seed germination. In this study, a barley aldehyde oxidase 1 (HvAO1) gene was identified, which is located near the SD2 (seed dormancy 2) region at the telomeric end of chromosome 5H. A doubled-haploid population (AC Metcalfe/Baudin) was used to characterize HvAO1 and validated its association with seed germination and malting quality. Aldehyde oxidase is predicted to catalyse the oxidation of various aldehydes, such as indoleacetaldehyde and abscisic aldehyde, into IAA and ABA, which is the final step of IAA/ABA biogenesis. This process influences the final IAA/ABA concentration in the seed, affecting the seed dormancy. Sequence analysis revealed substantial variations in the HvAO1 promoter regions between AC Metcalfe and Baudin. The combining seed germination tests, genetic variation analysis, gene expression, and phytohormone measurements showed that Baudin, which displays strong seed dormancy, has a specific sequence variation in the promoter region of the HvAO1 gene. This variation is associated with a higher expression level of the HvAO1 gene and an increased level of ABA than those in AC Metcalfe, which shows weak dormancy and lacks this sequence variation. In addition to its strong effect on the SD2 gene, HvAO1 shows excellent potential to fine-tune malting quality and seed dormancy, as evidenced by genotyping with HvAO1-specific markers, dormancy phenotypes, and malting quality. Our findings provide a new strategy for introducing favourable HvAO1 alleles to achieve the desired level of seed dormancy and high malting quality in barley.

A morphology-based growth stage system should describe the growth and development of a crop and thereby help farmers and agronomists in formulating reasonable managementmeasures conducive to the development of marketable products. However, existing growth stage systems for soybean are either based on plant growth or covered particular phases of flower or pod development, making it difficult to use for tracking the entire growth period of individual flowers and pods. Therefore, the first flower and pod, located at the base of the primary raceme in the eighth trifoliate node of the main stem, were chosen to illustrate growth dynamics during the full reproductive period. The size and fresh weight of the primary raceme in the eighth trifoliate leaf axil, the first flower and pod, the pistils in the first flower, and seeds in the first pod were examined, and the growth of these organs was depicted. Integrating the morphological characteristics and growth features of flowers and pods, as well as existing growth stage systems, the growth and development were delineated in 13 stages. In detail, we classified the flower phase based on the relative positions of floral components, inspired by the ratio of bract to flower used for staging, refined the lag phase proposed previously, retained the use of pod length to define the early pod phase, and innovatively described the late pod phase by the seed appearance. The developmental events in each stage of flower and pod were distinctive and closely connected to the corresponding morphology. Taken together, a more detailed growth stage system for describing individual flowers and pods in soybean was established. This system will serve as a valuable research tool for describing the development, gene expression, and cellular metabolism associated with the formation of flowers, pods, and seeds.