The interactions between nematodes and fungi are important for soil carbon cycling. However, their cascading effects on soil organic carbon (SOC) accrual remain unclear, particularly the role of soil aggregates and manure amendments in mediating this trophic cascade. Using a 19-year fertilization experiment, we examined how nematode predation influences fungal necromass carbon (FNC) and glomalin-related soil proteins (GRSPs), and quantified their contributions to SOC across soil aggregates under different manure amendments. Our findings showed that nematode predation significantly enhanced fungal biomass and promoted deterministic assembly of fungal communities. These effects were strongly dependent on aggregate size, with the most pronounced responses observed in the large macroaggregate (LA) fraction. A complementary microcosm experiment confirmed that nematode predation increased fungal biomass by over 6%, particularly in the LA fraction. Manure amendments further stimulated fungal growth and reinforced deterministic community assembly, thereby enhancing trophic cascade-driven accrual of FNC and GRSPs. Of the two fungal-derived carbon sources, FNC contributed more substantially to SOC (40%) than GRSPs (17%), with the greatest contribution found in the LA fraction. Path analysis further revealed that nematode-induced changes in fungal communities mediated the positive effects of manure amendments on fungal-derived carbon accrual. Overall, these findings underscore the pivotal role of nematodes in driving positive trophic cascade impact on SOC accrual. Our study offers new insights into aggregate-scale carbon dynamics and biologically mediated strategies for soil carbon management.

Chemical fumigants such as dazomet (DZ) and dimethyl disulfide (DMDS) effectively suppress soil-borne pathogens but there is uncertainty regarding the restoration of soil ecological functions in continuous cropping obstacles after fumigation, such as microbe-mediated organic carbon cycling. However, the mechanism by which microbial remediation measures enhance carbon mineralization activity after soil fumigation remains unclear. In this study, we conducted microcosm experiments to investigate the impacts of Bacillus velezensis inoculation on exogenous organic carbon (EOC) mineralization and bacterial community composition and interactions following chemical fumigation. Relative to fumigation alone, B. velezensis addition increased cumulative EOC mineralization by 27% in DZ-treated soils and by 22% in DMDS-treated soils. This enhancement was associated with the enrichment of core taxa and keystone species, which collectively increased microbial activity. Structural equation modeling further confirmed that core taxa (OTU56, belonging to Bacillus) induced positive interactions with indigenous species, which drove the observed enhancement in EOC mineralization. We conclude that B. velezensis facilitates the rapid recovery of soil carbon mineralization after fumigation by selectively reshaping the bacterial community and strengthening bacterial cooperative networks. This work provides a mechanistic framework for microbially driven ecological restoration of fumigant-impacted continuous-cropping obstacle soils and informs the development of sustainable soil-management practices in chemically challenged agroecosystems.

The auxin response factor (ARF) is the key component of phytohormone auxin signal pathway and is crucial in regulating a plurality of functions throughout the plant life cycle.  Although ARFs’ structure and function have been well studied in Arabidopsis, such knowledge is far from being sufficient for cereal crops, especially wheat, rice, and maize.  This review is based on a comprehensive retrospection into the studies on ARFs in the three cereal crops, consisting of four parts: (1) characterization of the domains of 23, 25, and 33 ARF family members in wheat, rice, and maize, respectively; (2) revision of nomenclatures for previously reported ARFs to the family numbers based on sequence alignment, and summary of ARFs’ functions including the regulation of agronomic traits and response to biotic/abiotic stresses; (3) highlight of general regulatory models for fundamental physiological and reproductive traits from miRNA-ARFs, IAA-ARF-LBD, IAA-ARF-Auxin response gene, and IAA-ARF-ERF (4) prospects to promising future ARF research for anticipated agronomic traits.  This review is expected to enhance understanding of ARF functions in the three cereal crops and promote their application in molecular breeding to achieve optimal plant architecture, higher yield, and wider adaptability.

The inflorescence and spikelet structural units of rice significantly impact grain development.  Among the grasses, the sterile lemma represents a unique spikelet organ exclusive to rice.  As most studies on sterile lemma genes primarily focus on Asian cultivated rice (Oryza sativa L.), genes influencing the sterile lemma phenotype in African rice remain unreported.  This study identified lsl3, a gene located on the short arm of chromosome 7 that controls the sterile lemma length in African rice.  The key mutation of lsl3, leading to long sterile lemmas in African rice, was discovered and differed from that in Asian rice.  The investigation of lsl3 not only provides a reference for the molecular evolution of cultivated rice in Africa but also offers new evidence supporting the parallel domestication of rice and the independent origin of Oryza glaberrima.

Fusarium head blight (FHB) is one of the most important and destructive wheat diseases worldwide, threatening both food security and safety.  In this study, a recombinant inbred line (RIL) population with 269 F₆ lines developed from a cross between ‘Nanjing 8611’ and ‘Ocoroni’ was used to map quantitative trait loci (QTLs) for FHB resistance.  Field FHB trials were conducted for three years in Nanjing, China, using point inoculation, and two years in Mexico with spray inoculation.  A high-density genetic map was constructed for the RIL population using the wheat 55 K single nucleotide polymorphism (SNP) array.  A total of 13 QTLs were detected on chromosomes 1B, 2D, 3B, 5D, 6D, and 7A, among which two major QTLs, QFhb.CIM-2D.1 and QDon.CIM-3B.1, were stably expressed in this study.  Conditional QTL analysis suggested that QFhb.CIM-2D.1 contributes to reduced deoxynivalenol (DON) content via decreasing FHB severity, whereas QDon.CIM-3B.1 contributed to FHB resistance by directly controlling DON accumulation.  Stacking of QFhb.CIM-2D.1 and QDon.CIM-3B.1 exhibited a marked increase in resistance against both FHB and DON.  Furthermore, two Kompetitive Allele-Specific PCR (KASP) markers, KASP-1369 and KASP-8394, tightly linked to QFhb.CIM-2D.1 and QDon.CIM-3B.1, respectively, were developed and successfully validated in their respective genetic populations.  Altogether, these results broaden the understanding of the genetic basis of resistance to FHB, and the developed markers are valuable for marker-assisted wheat breeding.  

Roots are vital for crop growth, development, yield, and tolerance to various types of environmental stress.  Numerous genetic loci associated with soybean root morphological traits have been identified, but few genes associated with these traits have been reported.  This study identified seven quantitative trait loci (QTLs) containing stable SNPs significantly associated with the root dry weight in soybeans through a genome-wide association study.  Among these QTLs, qRDW14-2 presented the greatest significance.  In qRDW14-2, the gene GmRGD14, encoding the lysophosphatidic acid acyltransferase LPAT4, was identified as a candidate.  GmRGD14, in block63, which contained the significant SNP S14_6521715, had the highest expression level in soybean roots, and its Arabidopsis homologous mutant lpat4 presented more lateral roots than did the control Col-0.  GmRGD14 was localized primarily to the cell membrane and endoplasmic reticulum.  The heterologous overexpression of GmRGD14 in Arabidopsis significantly increased the lateral root number, which was similar to the phenotype of atlpat4.  Furthermore, overexpression of GmRGD14 resulted in a greater total root length, root tip number, root surface area, and root volume in the hairy roots of transgenic soybean plants than in those of control soybean plants, whereas knockdown of the gene via RNA interference in soybean hairy roots resulted in the opposite phenotype.  GmRGD14, which is highly genetically variable in wild soybean, has been gradually utilized during soybean domestication.  Overall, this study revealed that GmRGD14 is a new key gene involved in root growth, providing a promising genetic target for breeding elite soybean varieties with strong root systems.

Rapeseed (Brassica napus) is one of the most important oil crops worldwide and provides a major source of edible vegetable oil.  Currently, manipulating plant height with branching effectively balances biomass and yields.  However, the genetic mechanisms to control plant height remain largely unknown in rapeseed.  To address this gap, we isolated an extremely dwarf mutant (dm1) from ethyl-methanesulfonate (EMS) mutagenesis and revealed that the dwarfism results from a significant reduction in cell length.  Bulk segregant analysis (BSA) identified BnaA10.CYP90A1 and BnaC09.CYP90A1 as the causative genes of dm1.  Both genes encoded the proteins homologous to the Arabidopsis cytochrome P450 AtCPD/AtCYP90A1, which is crucial for brassinosteroid (BR) biosynthesis.  In this regard, we demonstrated reduced levels of bioactive BRs, castasterone (CS), and its precursor 6-deoxoCS in dm1, resulting in down-regulation of various genes involved in cell expansion.  The reduced BR levels also caused negative feedback, promoting the expression of BR biosynthetic genes in dm1.  Furthermore, we proved that the single mutation of BnaA10.CYP90A1 gene conferred semi-dwarfism, potentially beneficial for producing an ideal type of plant to improve cultivars with a balance of yield and machinery harvest through genetic modifications.  Collectively, these findings highlighted the critical role of BnaCYP90A1s in BR biosynthesis and validated their influence on plant height regulation in rapeseed.

This study investigated the role of jasmonates (JAs) in mitigating the impairment of high temperature (HT) stress-induced spikelet opening in photo-thermosensitive genetic male-sterile (PTGMS) rice under controlled moderate soil drying (MD).  Two PTGMS rice varieties were grown under normal temperature (NT) and HT conditions, paired with either well-watered (WW) or MD strategies during anthesis, in both controlled-climate pot and open-air field conditions over multiple years.  The MD treatment demonstrated significant protective effects compared to the conventional WW regime under HT stress, which significantly reduced the levels of JAs in lodicules and worsened spikelet opening impairment and hybrid seed yield loss.  The MD regime enhanced the accumulation of JAs in lodicules, effectively alleviating HT-induced spikelet opening impairment and hybrid seed yield reduction.  This protective mechanism operates through multiple pathways: (1) promoting starch hydrolysis into soluble sugars, (2) upregulating the expression of aquaporin genes, and (3) enhancing antioxidant capacity, thereby maintaining cellular osmotic and redox homeostasis in the lodicules.  The crucial role of JAs in this mechanism was confirmed using JA-deficient mutants, transgenic rice lines with varying JA biosynthetic capacities, and exogenous applications of JAs.  These findings indicate that MD is a more effective cultivation strategy than traditional WW in protecting PTGMS rice from HT stress, which is achieved by modulating levels of JAs to maintain osmotic and redox homeostasis in the lodicules, thus improving spikelet opening and hybrid seed yield under HT stress during anthesis.