New Crops最新文献

Elevated sodium ion (Na⁺) in saline farmlands adversely affect crops, notably by inhibiting seed germination. Given the importance of High-Affinity K⁺ Transporter (HAK) family Na⁺ transporters in plant salt tolerance and ZmHAK4 role in maize salt tolerance, our study focuses on characterizing HAK transporters related to ZmHAK4 in maize’s salt stress response. We found that ZmHAK17 is vital for promoting seed germination under saline conditions. Expressed mainly in the germinating embryo’s radicle, ZmHAK17, encodes a Na⁺ transporter located in the plasma membrane. Increased ZmHAK17 transcript levels under salt stress facilitate Na⁺ efflux from the radicle, preventing Na⁺ accumulation in the embryo and reducing salt stress effects on germination. Mutants lacking ZmHAK17 exhibit salt-sensitive germination. This study highlights ZmHAK17 as a key transporter enhancing maize germination in saline conditions, deepening our understanding of HAK family Na⁺ transporters’ role in salt tolerance and offering a new target gene for salt-tolerant maize breeding.

Under global climate change circumstances, there has been growing acknowledgment of the critical need to prevent and manage both biotic and abiotic stress in crops. Plants employ a variety of signaling molecules, such as jasmonic acid (JA), abscisic acid (ABA), and Ca²⁺, to endure stress. Additionally, they utilize reactive oxygen species (ROS) and detoxifiers while also harnessing the assistance of beneficial microorganisms, including Bacillus, Pseudomonas, Streptomyces, and others. These microorganisms play a pivotal role in aiding crops in stress management, albeit with certain limitations to their efficacy. This article offers a synthesis and discourse on how crops can selectively engage with beneficial microorganisms via their root systems, elucidating the contributions of these microorganisms to stress tolerance. Drawing upon current insights, we propose refined strategies for leveraging microorganisms to bolster crop stress resilience. By advancing our grasp of plant-microorganism interactions and judiciously selecting and employing beneficial microorganisms, we aim to enhance the dependability and efficacy of microbial products in enhancing crop stress tolerance. This knowledge ultimately equips agricultural practitioners with the information needed to make informed decisions and bolster crops in adapting to rapidly changing environmental conditions.

Stomata are tiny pores on leaf surfaces essential for plant transpiration and photosynthesis. As gatekeepers that mediate gas exchange between plants and the atmosphere, stomata exert a major influence on global carbon and water cycles. The shape and function of stomata are physically constrained by stomatal walls. Compared to the extensively studied genetic mechanisms of stomatal development and guard cell signaling, recent progress is only beginning to uncover the role of plant cell walls in stomatal development and dynamics. In this review, we summarize the research on cell walls of the kidney-shaped stomata from dicots and the dumbbell-shaped stomata from grasses. As the dynamic response of grass stomata is closely linked to its anatomical features that are limited by cell walls, we discuss the potential of plant cell walls as crucial targets for crop engineering to enhance carbon assimilation and water use efficiency.

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.