Journal of Integrative Plant Biology最新文献

The unfolded protein response (UPR) serves as a crucial regulatory mechanism that enables eukaryotic cells to mitigate endoplasmic reticulum (ER) stress and plays a significant role in plant antiviral immunity. In this study, we show that V2 protein encoded by the tomato yellow leaf curl virus (TYLCV) induces severe necrotic symptoms in Nicotiana benthamiana and tomato plants. V2 activates the host UPR, and this activation promotes TYLCV infection. Furthermore, we demonstrate that V2 directly interacts with NbFKBP13, a rate-limiting enzyme in protein folding, and inhibits its enzymatic activity. Genetic analysis revealed that NbFKBP13 significantly attenuates V2-induced UPR activation and cell death while enhancing N. benthamiana resistance against TYLCV infection. Similarly, V2 interacts with SlFKBP13, the tomato homolog of NbFKBP13, and SlFKBP13 improves tomato resistance to TYLCV infection. Moreover, both TYLCV infection and V2 expression induce autophagy, a process in which NbFKBP13 plays a crucial role. Notably, the activation of autophagy inhibits TYLCV infection. Our results unveil a molecular mechanism through which the geminivirus V2 protein manipulates the host UPR to facilitate viral infection. These findings significantly advance our understanding of the evolutionary arms race between plants and viruses.

Alkaloids, renowned for their pivotal physiological roles in plant defense and chemical medium, constitute a structurally diverse class of bioactive natural products with substantial therapeutic potential in modern drug development. There is currently no dedicated alkaloid database, highlighting an urgent need for such a resource. Here, we present AlkaPlorer (https://alkaplorer.qmclab.com/), the first systematic alkaloid database, which has compiled over 130,000 alkaloids from 12,250 species, with reported activity against 6,583 biological targets. AlkaPlorer not only integrates comprehensive experimentally validated data and computationally predicted properties for each alkaloid, but also establishes standardized notation and associations among various data elements, forming a correlative-type dataset. Extensive chemoinformatic analyses on structural scaffolds, biosynthetic precursors, physicochemical properties, and phylogenetic distributions across plant taxa are performed based on AlkaPlorer, providing new insights into the chemical diversity, structural evolution, and biosynthetic regularity of plant alkaloids. AlkaPlorer enables easy access and efficient retrieval and provides a foundational resource for AI-driven applications in plant metabolism and alkaloid research.

THESEUS1 (THE1) is a component of the CrRLK1L-RALF signaling complex specifically responsible for establishing the polytubey block at the Arabidopsis septum. Genetic and biochemical analyses demonstrate that THE1, together with FERONIA, ANJ and HERK1, forms a receptor complex that senses pollen tube-derived RALF peptides, thereby establishing a barrier to prevent the emergence of multiple pollen tubes from the septum.

Mitogen-activated protein kinase (MAPK) cascades play vital roles in regulating plant growth, development, and stress responses. Nevertheless, the complete MAPK cascade that regulates the flowering time of Arabidopsis thaliana has not been established. A MAPK module comprising MAPKKK18, MAPKK3, and MAPK1/2/7/14 accelerates flowering in Arabidopsis. Through direct interaction, MAPK1/2/7/14 phosphorylates the S²⁴ residue of NF-YB2. Phosphorylated NF-YB2 enhances the stability of the heterotrimeric CO ~ NF-YB2 ~ NF-YC3/C9 complex and the expression of FT. Accumulation of NF-YB2 significantly promotes flowering, whereas the role of NF-YB2^S24A in this process is less pronounced. Compared with the transgenic plants overexpressing MAPKKK18 in the wild-type (WT) background, the nf-yb2 plants overexpressing MAPKKK18 bolt considerably later. Taken together, the MAPKKK18-mediated signaling cascade exerts tight control over the flowering time of Arabidopsis by modulating the phosphorylation status of NF-YB2, unveiling a flexible regulatory pathway to fine-tune plant development.

Tension wood (TW), a type of reaction wood that develops in angiosperm trees in response to gravistimulation, serves as an ideal model for investigating the regulatory mechanisms underlying xylem cell differentiation and cell wall deposition. The initial biological signals that induce the formation of reaction wood in response to gravitational stimuli remain poorly understood. In this study, we utilized pharmacological and genetic approaches to modulate Ca²⁺ levels in hybrid white poplar (Populus alba × P. glandulosa) and examine the role of calcium signaling during the early stages of gravitropic responses. Our findings revealed differential cytosolic Ca²⁺ signal distribution in gravistimulated stems during the early phase of gravity induction, characterized by lower Ca²⁺ levels on the upper side (where TW forms) and higher Ca²⁺ levels on the lower side (where opposite wood forms). Consistent with this hypothesis, plants treated with LaCl₃ and those with genetically disrupted calcium channels (PagGLR3.3 knockout using the CRISPR/Cas9 system) showed reduced Ca²⁺ signals and developed characteristic TW features. These results suggest that decreased Ca²⁺ levels induce the formation of TW. Furthermore, PagGLR3.3 knockout plants with TW-like stems displayed diminished sensitivity to gravistimulation. Transcriptomic analysis revealed that the knockout of PagGLR3.3 resulted in the upregulation of genes associated with TW formation and reactive oxygen species (ROS) production. Notably, superoxide anion (O₂ ^·-) levels were significantly elevated in the cambium zone of stems subjected to gravistimulation, LaCl₃ treatment, or PagGLR3.3 knockout, indicating that reduced Ca²⁺ levels promote TW formation through increased O₂ ^·- accumulation. This study offers novel insights into the critical role of Ca²⁺ in gravitropism and TW induction in poplar.

Modifying the light formula is a central strategy for improving the yield and quality of fruits and vegetables in agriculture. While light signals have long been acknowledged as primary factors in regulating plant growth and development, their role in reprogramming metabolic networks is not well understood. Using tomato as a model, we demonstrate that supplementation with red or blue light induces metabolic shifts in tomato fruit. Through the creation of the Tomato Light-induced Expression Database (TomLED), we identified extensive transcriptomic and metabolic changes in tomato fruit under varying light conditions. Notably, the induction of key master regulators and metabolic genes is mediated by increased genome-wide DNA demethylation, facilitated by SlDML2. Additionally, we show that SlHY5, a central regulator in the light signaling pathway, directly induces the expression of SlDML2. This study reveals the molecular mechanisms by which light regulates the plant epigenome and establishes a direct link between light signals and plant metabolism.

Seed oil accumulation is an important process affecting seed quality, and regulatory factors modulating this process remain less understood, especially in soybean. In this study, through RNA-seq and gene co-expression network analysis, we identified a single MYB (Myeloblastosis)-type transcription factor GmMYB331, which promotes seed oil accumulation in soybean seeds and enhances seed size/weight as well. Transgenic soybean plants with mild GmMYB331 overexpression showed higher total fatty acid contents in seeds and higher seed yield per plant compared to the control plants. In contrast, transgenic soybean plants with strong GmMYB331 overexpression showed only increased seed size/weight but much reduced seed yield per plant, along with an altered plant architecture. Knocking out GmMYB331 by CRISPR/Cas9 produced mutants with less total fatty acids, smaller seeds, and less seed weight, indicating that the gene is required for oil accumulation and seed size/weight control. GmMYB331 may achieve these functions by differential binding to the gene promoters and activation of the downstream genes, namely, GmOLEO1/2/4 for oil accumulation in mild overexpressing plants and GmCYCD2;2 for seed size/weight increase in strong overexpressing plants. Our study reveals a possible mechanism involving differential regulation by GmMYB331 toward oil accumulation and seed size/weight increase. Manipulation of the GmMYB331 gene may facilitate breeding for high-oil and/or -yield soybean cultivars.

Wild perennial sister species Medicago archiducis-nicolai (rhizomatous/alpine) and M. ruthenica (non-rhizomatous/xeric) constitute vital genetic resources for forage improvement. To decode the genomic basis of their contrasting trait and habitat adaptation, we generated chromosome-scale genome assemblies, resequenced 128 individuals, profiled transcriptomes under cold/heat stress, and functionally validated causal alleles. We demonstrate that structural variations (SVs)-particularly gene duplications-are primary drivers of rhizome formation and alpine/xeric adaptation. Further, pervasive presence-absence SVs (PAVs) in noncoding regulatory regions underpin divergent allele-specific expression governing rhizome development and stress responses. Crucially, these regulatory PAVs induce contrasting expression patterns during trait development and stress adaptation. Our findings reveal a dual mechanism whereby coding and regulatory SVs convergently orchestrate phenotypic innovation and ecological specialization in sister species, offering valuable genomic resources for legume evolution studies and alfalfa breeding.

Leaf morphology varies substantially across plant species. In soybeans, the regulation of compound leaf development remains poorly characterized, despite its critical role in plant architecture. Some soybean cultivars have compound leaves with up to five leaflets, while most are trifoliolate. Using genetic mapping, we identified a gene behind the leaflet number variation as LF1, an AP2/ERF transcription factor. High expression levels of LF1 were further observed in leaf primordium initiation sites, leaf primordia, and leaflet initiation domains. Transgenic overexpression of LF1 increased leaflet number. Further investigation revealed that LF1 regulates leaflet development through negative autoregulation via GCC-box cis-element binding. In addition to the role of LF1, the CRISPR-edited mutant of TEOSINTE-BRANCHED1/CYCLOIDEA/PCF3 (GmTCP3) displayed serrated blade margins in juvenile leaves and increased compound leaflet numbers. Protein interaction assays confirmed LF1 binding affinity for GmTCP3. Furthermore, we demonstrate that LF1 induces the expression of GmLFY, a key regulator of leaflet development. Altogether, our findings establish LF1 as a central regulator of soybean leaflet morphogenesis and reveal its mechanistic interactions with GmTCP3 and LEAFY (GmLFY), offering novel mechanistic insights into the genetic control of compound leaf development.

Rice is one of the most important food crops in the world and it is prone to attack by many diseases, such as the rice blast, sheath blight, bacterial leaf blight, and so on. These diseases represent the main constraints in rice production, threatening food security and safety. Here, new control strategies against these major rice diseases have been developed either by heterologous expression of a pathogen effector UvScd1 from false smut fungus Ustilaginoidea virens or by spraying the engineered biocontrol agent Bacillus subtilis secreting the effector UvScd1. Compared to the wild-type rice Zhonghua11 (ZH11), the rice line heterologously expressing UvScd1 showed lesion mimics and upregulated the expression of defense-related genes in leaves, including genes related to the JA and SA signaling pathways. As expected, the transgenic rice line showed broad-spectrum resistance to hemibiotrophic fungus Magnaporthe oryzae, necrotrophic fungus Rhizoctonia solani, and bacterium Xanthomonas oryzae pv. oryzae (Xoo), while there was no effect on yield-related agronomic traits compared with ZH11, suggesting that the effector UvScd1 confers both plant resistance via induction of ROS and defense-related genes, and maintains the balance between plant resistance and yield. In field experiments, comparable control efficiencies against these major rice diseases were achieved by spraying B. subtilis engineered to secrete UvScd1 and corresponding chemical pesticides, underscoring that use of biocontrol agents to secrete certain pathogen effector proteins is an effective strategy for the management of plant diseases. It is noteworthy that the application of B. subtilis engineered to secrete UvScd1 also achieved effective control for a variety of crop diseases, suggesting its excellent potential for use in practice.