New Crops最新文献

Higher plants must coordinate their own growth and development by responding to a myriad of internal signals. Simultaneously, confronted with external signals such as pathogen invasion, drought and so on, they must constantly adjust themselves to adapt. These signals can be specifically recognized by transmembrane receptors on the cytoplasmic membrane, comprising receptor kinases (RKs) and receptor-like proteins (RLPs). Among these, leucine-rich repeat receptor kinases (LRR-RKs) and leucine-rich repeat receptor-like proteins (LRR-RLPs) form the largest category. By using X-ray crystallography and cryo-electron microscopy (cryo-EM) single-particle analysis, the ligand recognition and receptor activation mechanisms of some LRR-RKs/RLPs have been elucidated at the atomic scale. This deepens our understanding of the roles played by LRR-RKs/RLPs in the plant growth, development, responses to pathogen invasion and other environmental stresses. Moreover, it provides clues for precise genetic improvement aimed at improving yield, quality and stress resistance in economic crops. This review summarizes the recent progress in structural research on LRR-RKs/RLPs concerning plant growth, development, immune responses and other environmental stress responses. Additionally, this paper discusses how these receptors recognize their respective ligands and how ligand recognition triggers receptor activation from a structural biology perspective, offering new insights for crop improvement.

Extended natural and artificial selection have introduced pronounced differences throughout the genomes, morphological traits, and geographical distributions of the two predominant rice strains, Oryza sativa Xian/indica (XI) and O. sativa Geng/japonica (GJ). However, the unique roles of natural and artificial selection in strain differentiation remain uncharacterized. Therefore, we independently produced advanced inbreeding populations in typical GJ- and XI-cultivated areas, beginning from the F₂ generation. We utilized pedigree and bulk-selective methods to characterize artificial and natural selection, respectively. Our examination uncovered preferences between artificial and natural selection. Artificial selection was favored by individuals with increased grain count per panicle but reduced panicle number, while natural selection favored traits like greater panicle number, reduced grains per panicle, and higher thousand-grain weight, especially in the XI cultivation areas. Notably, in the XI regions, natural selection produced a preference for wider grains, indicating that the elongated grains in XI rice may be caused by artificial rather than natural selection. Using de novo assembly of a high-quality parental genome, we observed an increased prevalence of the GJ genotype in GJ areas compared to XI areas, segregation distortion in the advanced inbreeding population could be attributed to loci regulating hybrid sterility. Notably, the semi-dwarf allele sd1-d, linked to the “Green Revolution”, was not favored in either selection paradigm in northern areas, possibly due to its disadvantages on grain yield per plant and NH₄⁺ uptake rate. Our study offers novel perspectives into the contributions of natural and artificial selection to the divergence between XI and GJ subspecies.

RNA interference (RNAi) is an efficient molecular approach in which double-stranded RNA (dsRNA) can effectively knock down the expression of certain genes, promoting mRNA degradation, and gene function loss. Based on the principle of RNAi, a novel and eco-friendly biopesticide has been characterized and used in recent years. RNAi-based biopesticides have high specificity, efficiency, and easy degradation, which have ushered in the third revolution in the history of pesticides. Additionally, these properties of RNAi-based biopesticides are of great significance in achieving sustainable agricultural development. However, before the market release of any biopesticides, it is essential to consider whether they will adversely affect human health and the environment. This paper reviews RNAi-based biopesticides' different modes of action and the diverse associated risks, such as environmental risk (environmental fate, off-target effects, exposure assessment, and resistance development), human health risk, and government policies.

Powdery mildew, a widespread and destructive wheat disease caused by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt), results in significant yield losses globally. Employing host resistance is the most cost-effective and environmentally sustainable approach to managing this disease. Assessing the resistance levels of wheat germplasms and understanding the genetic underpinnings of this resistance is crucial. In this study, we evaluated the seedling resistance to powdery mildew in 558 wheat accessions, along with the presence of resistance genes Pm1, Pm2, Pm4, Pm5, Pm6, Pm8, Pm12, Pm21, Pm24, Pm41, Pm42, Pm45, Pm47, Pm60, and Pm69 using various Bgt isolates and associated diagnostic markers. The study revealed that out of 558 wheat accessions tested, only 25 showed resistance to the Bgt isolate E09, highlighting a general lack of powdery mildew resistance among the evaluated accessions. Furthermore, these 25 accessions exhibited a significantly different resistance spectrum to 25 additional Bgt isolates. Notably, seven of these accessions were resistant to all the tested isolates, indicating they possess Pm genes with broad-spectrum resistance. Molecular analysis using closely linked or diagnostic markers revealed diverse resistance gene profiles: 249 accessions harbored a single tested Pm gene, 75 accessions possessed combinations of Pm genes, and 234 accessions lacked any of the tested genes. Pm8 was the most frequently detected gene, present in 27.42% of accessions, whereas Pm5, Pm12, Pm24, Pm41, Pm42, Pm45, Pm47 and Pm69 were not detected. Among the seven accessions resistant to all 26 tested isolates, Pm21 was detected in four accessions (HengS29, Chang 4640, Xinong 556, and ML728). Pm2 and Pm60 were identified in Emai 18 and Xinmai 296, respectively. Interestingly, none of the tested genes were detected in Emai 16, suggesting the presence of potentially novel Pm gene(s) conferring broad-spectrum resistance. These findings offer valuable insights for the strategic dissemination of these resistant accessions and for targeted breeding programs aimed at combating powdery mildew.

Plant diseases caused by various pathogenic microorganisms can cause substantial reductions in agricultural crop yield and quality, resulting in significant economic losses and posing a threat to global food security. Understanding the mechanisms of plant-pathogen interactions is essential for developing genetic strategies to safeguard crops against disease. Ralstonia solanacearum, a soil-borne pathogen of significant importance, has emerged as a prominent model for studying plant-pathogenic bacteria due to its extensive genetic diversity, prolonged environmental persistence, unusually broad host range, and notably, its considerable impact on agriculture. To successfully invade and propagate in plants, R. solanacearum employs diverse extracellular pathogenic factors and intracellular type III effectors (T3Es) to evade or disrupt plant immunity. In response, plants have evolved a two-layered innate immune system, represented by pattern-triggered immunity (PTI)—mediated by cell-surface pattern recognition receptors (PRRs) and effector-triggered immunity (ETI)—mediated by intracellular nucleotide-binding and leucine-rich repeat receptors (NLRs). Over the past three decades, many factors contributing to the dynamic interactions between R. solanacearum and plants have been identified. This comprehensive overview aims to summarize the current understanding of R. solanacearum extracellular virulence factors and intracellular T3Es, as well as host plant PRRs recognizing characterized PAMPs (pathogen-associated molecular patterns), and plant NLR-mediated recognition of avirulent T3Es that govern plant host-R. solanacearum interactions. Additionally, we highlight current endeavors aimed at applying this knowledge to developing enhanced plant disease resistance tools, address prevailing challenges, and provide insights into future research perspectives.

Throughout legume–rhizobium symbiosis, nitrogen fixation occurs within the symbiosome, a membrane-bound organelle-like structure found in nodule cells. The symbiosome represents a temporary organelle in which rhizobia-encoded nitrogenase catalyzes dinitrogen conversion to ammonia in an oxygen-regulated microenvironment. Investigating symbiosome biology will undoubtedly improve our understanding of nitrogen fixation mechanisms and highlight novel targets for improving nitrogen fixation efficiency. Recent research advancements have taken place on regulatory aspects of symbiosome generation and functions, but obtaining spatiotemporally resolved symbiosome proteome and metabolomes, as well as tracking and deciphering its intracellular communication, is challenging. As a symbiotic interface, the symbiosome membrane proteome is largely composed of plant-derived proteins, while the symbiosome space between the symbiosome membrane and bacteria consists of proteins and metabolites from the rhizobium and plant. In the unique microenvironment, symbiosome proteins likely perform multiple tasks via their moonlighting functions, accounting for the many unsolved questions associated with symbiotic nitrogen fixation. In this review, we outline the current knowledge regarding the composition and potential moonlighting functions of symbiosome proteins. We highlight our current understanding of emergent symbiosome properties closely tied to nitrogen fixation activity. Ultimately, we discuss the challenges and opportunities for discovering new paradigms in symbiosome biology using recently developed technologies.

Plant root systems are critical for absorbing water and nutrients and anchoring plants in the soil, and their development is regulated by phytohormones and complex signaling pathways. Recent studies have identified small peptides as essential players in governing root development, binding to specific receptors on the cell membrane, and triggering signaling processes. In this study, we summarize recent advances in small peptide regulation of root system architecture and tissue organization, as well as the molecular interaction between peptides and canonical hormone signaling. Additionally, we discuss the functions of small peptides in modulating root development responses to environmental forces like nitrogen and phosphate starvation, osmotic stress, and soil microbes through the activation of local and systemic signaling pathways. This review offers a comprehensive overview of peptide signaling during plant root development and prospects for further crop breeding applications.

Establishing global sustainable agriculture emerges as the primary, indispensable strategy to meet escalating food demands and address environmental preservation amidst the challenges posed by severe climate change. The intricate communities of microorganisms associated with plants, collectively termed the plant microbiome, wield significant influence over the vitality and productivity of plant species. Unleashing the potential of the plant microbiome stands as a pivotal approach to safeguard and rejuvenate our planet. However, the complex nature of microbiome interactions, coupled with their limited persistence in intricate environmental settings due to gaps in understanding or technological limitations, has impeded substantial progress in this field. This review explores innovative and revitalized strategies for harnessing microbiome-based enhancements in crop fitness. Additionally, we illuminate the challenges encountered in deciphering the intricate interplay between the microbiome and its host, particularly in the context of mitigating the adverse influences of climate change on crop resilience. To navigate these complexities, we advocate for a comprehensive approach that considers both host and microbiome-oriented perspectives. This dual-focused strategy aims to overcome current limitations and pave the way toward a future where microbiome intervention forms the bedrock of sustainable agriculture and environmental protection.

The growth and yield of essential crops, including maize, are significantly endangered by drought. Closing stomata, limiting water dissipation, and improving water use efficiency are important components of plant drought responses. In our study, the MYB-like transcription factor ZmMYB56, expressed in maize guard cells, played important roles in regulating stomatal closure and drought tolerance. Mutations in ZmMYB56 triggered elevated stomatal conductance, rapid water loss in isolated leaves, and severe drought sensitivity in plants. ZmMYB56 possesses transcriptional activation activity, and is expressed specifically in stomatal guard cells. As an R2R3 transcription factor, ZmMYB56 can bind the cis-acting element on the ZmTOM7 promoter sequence, activating its expression. Correspondingly, the ZmTOM7 transcript level is downregulated in Zmmyb56 seedlings. Transgenic Arabidopsis plants overexpressing ZmTOM7 exhibit limited stomatal conductance and elevated drought tolerance, while the ZmTOM7 mutation is linked to higher stomatal conductance and substantial drought sensitivity in maize seedlings. According to these findings, we conclude that ZmTOM7 operates as a key target gene of ZmMYB56 and is involved in ZmMYB56-regulated stomatal closure and maize drought tolerance. Our findings regarding the functional mechanisms of maize ZmMYB56 transcription factors in stomatal closure and drought stress enable a potential genetic resource for improving the drought resistance of maize.

Roots play a fundamental role in plant growth and development, serving various functions, including anchoring, water absorption, nutrient uptake, and adaptation diverse environmental conditions, such as abiotic stresses and biotic interactions. Arbuscular mycorrhizal (AM) fungi release diffusible signaling molecules known as mycorrhizal factors (Myc factors) to establish communication with plants. Extensive research has established that Myc factors play a pivotal role in orchestrating root architectural changes before fungal colonization occurs. In this study, we investigate the impact of the Myc factor CO4 on the architectural modifications of rice roots. Our findings reveal that CO4 actively promotes the development of crown roots and lateral roots in wild-type rice plants. Furthermore, we have identified that pivotal role of receptors such as OsCERK1, OsMYR1, and OsCEBiP in mediating the stimulatory effects of CO4. Knockout mutants of these receptors exhibit a significant reduction in the number of lateral roots and crown roots with lateral roots, along with decreased sensitivity to CO4. Conversely, the overexpression of OsMYR1 leads to a substantial increase in lateral roots and crown roots with lateral roots, even in the absence of CO4 treatment. We propose that CO4-induced root architecture development offers promising opportunities for enhancing lateral root growth, which, in turn, can promote nutrient uptake through direct Myc factor application.