Journal of Integrative Plant Biology最新文献

Hypoxia (low-oxygen tension) caused by complete submergence or waterlogging is an abiotic stress factor that severely affects the yield and distribution of plants. To adapt to and survive under hypoxic conditions, plants employ several physiological and molecular strategies that integrate morphological acclimation, metabolic shifts, and signaling networks. Group VII ETHYLENE RESPONSE FACTORS (ERF-VIIs), master transcription factors, have emerged as a molecular hub for regulating plant hypoxia sensing and signaling. Several mitogen-activated protein kinases and calcium-dependent protein kinases have recently been reported to be involved in potentiating hypoxia signaling via interaction with and phosphorylation of ERF-VIIs. Here, we provide an overview of the current knowledge on the regulatory network of ERF-VIIs and their post-translational regulation in determining plant responses to hypoxia and reoxygenation, with a primary focus on recent advancements in understanding how signaling molecules, including ethylene, long-chain acyl-CoA, phosphatidic acid, and nitric oxide, are involved in the regulation of ERV-VII activities. Furthermore, we propose future directions for investigating the intricate crosstalk between plant growth and hypoxic resilience, which is central to guiding breeding and agricultural management strategies for promoting flooding and submergence stress tolerance in plants.

Maintenance of endoplasmic reticulum (ER) homeostasis is central for plants to survive in changing cellular and environmental conditions. Although the role of ER in plant immunity is evident, how ER homeostasis is associated with activation of the immune response remains unclear. Here, we report that StDMP2, an ER-localized member of the DOMAIN OF UNKNOWN FUNCTION 679 membrane protein (DMP) family, positively regulates resistance to Phytophthora in potato (Solanum tuberosum). Heterologous expression of StDMP2 in tobacco (Nicotiana benthamiana) also enhances resistance to Phytophthora. Furthermore, StDMP2 is involved in both chemical- and pathogen-induced ER stress responses. Notably, StDMP2 plays a crucial role in several pathogen-associated molecular pattern-triggered immunity responses, and specifically contributes to the hypersensitive response triggered by the bacterial type-III secreted effector AvrRpt2, but not the Phytophthora infestans-secreted effector Avr3a. Further investigation revealed that StDMP2 affects the ER quality control-mediated accumulation of specific pattern recognition receptors and NON-RACE SPECIFIC DISEASE RESISTANCE 1. Collectively, these findings elucidate a mechanism by which StDMP2 promotes plant immunity through modulating ER homeostasis.

Tiller angle shapes plant architecture, and is one of the top traits in plant breeding. A compact plant type reduces shading between plants, especially at high planting density, but also creates a humid microenvironment often associated with a higher incidence of pathogen and pest attacks, especially under highly humid climates. However, how to precisely manipulate the tiller angle to achieve a desirable plant type has been under-approached. Here we report the creation of gradient tiller angles in indica rice by fine tuning the expression of TILLER ANGLE CONTROL1 (TAC1), a domesticated gene in cultivated rice. We edited the regions upstream and downstream of the TAC1 coding sequence using multiplex CRISPR-Cas9 technology and developed homozygous allelic lines carrying deletions/inversions of various sizes at different positions. Those lines displayed smooth gradient changes in tiller angle that aligned well with TAC1 expression levels. Additionally, changes in the TAC1 expression level had no impact on other agronomic traits examined. TAC1 is well conserved across species, including perennial fruit trees in which mutation of TAC1 orthologs leads to a broomy plant type. Thus, our results provide a guide to creating tiller angles for selection according to climate zones in rice breeding programs, this approach can be extended to diverse species for improving plant architecture.

The domains rearranged methyltransferases (DRMs) play a critical role in the RNA-directed DNA methylation (RdDM) pathway in plants. However, the effects of inactivating the RdDM pathway on gene expression, transposable element (TE) activity, and phenotype in soybean remain unexplored. Here, we employed clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 gene editing to generate a quintuple mutant line in soybean (Gmdrm2a^-/-2b^-/-2c^-/-3a^-/-3b^-/-, designated Gmdrm). Gmdrm exhibited severe developmental abnormalities, including dwarfism and delayed growth, albeit remaining viable and fertile; however, the fully homozygous mutant could be maintained for a limited number of generations (T0-T3). Whole genome bisulfite sequencing revealed a significant reduction in DNA methylation across all cytosine sequence contexts, with an average loss of 10%. The loss of ^mC was biased toward euchromatic regions, which is in contrast to the chromomethylase mutant. Transcriptome profiling identified 1,685 up-regulated genes, including photosynthesis-related genes, accompanied with altered chloroplast ultrastructure. Additionally, a cluster of resistance (R) genes on chromosome 16 was significantly up-regulated, coinciding with their reduced non-CG methylation. We also observed 3,164 differentially expressed TEs (DETs), of which, 2,655 were up-regulated and hypomethylated along their entire length. A substantial reduction in the abundance of 24-nt small interfering RNAs (siRNAs) in the Gmdrm mutant was detected by small RNA sequencing. Of note, the DRM-targeted TEs typically display higher levels of 24-nt siRNA abundance, shorter lengths, and are more AT-rich compared to chromomethylase-targeted TEs, highlighting 24-nt siRNAs as key determinants of DRM-dependent TE regulation. Together, this study documents a critical role of DRM-mediated DNA methylation in regulating gene expression, TE silencing, and normal development in soybean.

MYB transcription factors (TFs), one of the largest TF families in plants, are involved in various plant-specific processes as the central regulators, such as in phenylpropanoid metabolism, cell cycle, formation of root hair and trichome, phytohormones responses, reproductive growth and abiotic or biotic stress responses. Here we summarized multiple roles and explained the molecular mechanisms of MYB TFs in plant development and stress adaptation. The exploration of MYB TFs contributes to a better comprehension of molecular regulation in plant development and environmental adaptability.

In C₃ plants, photorespiration is an energy expensive pathway that competes with photosynthetic CO₂ assimilation and releases CO₂ into the atmosphere, potentially reducing C₃ plant productivity by 20%-50%. Consequently, reducing the flux through photorespiration has been recognized as a major way to improve C₃ crop photosynthetic carbon fixation and productivity. While current research efforts in engineering photorespiration are mainly based on the modification of chloroplast glycolate metabolic steps, only limited studies have explored optimizations in other photorespiratory metabolic steps. Here, we engineered an imGS bypass within the rice mitochondria to bypass the photorespiratory glycine toward glycine betaine, thereby, improving the photosynthetic carbon fixation in rice. The imGS transgenic rice plants exhibited significant accumulation of glycine betaine, reduced photorespiration, and elevated photosynthesis and photosynthate levels. Additionally, the introduction of imGS bypass into rice leads to an increase in the number of branches and grains per panicle which may be related to cytokinin and gibberellin signaling pathways. Taken together, these results suggest diverting mitochondrial glycine from photorespiration toward glycine betaine synthesis can effectively enhance carbon fixation and panicle architecture in rice, offering a promising strategy for developing functional mitochondrial photorespiratory bypasses with the potential to enhance plant productivity.

Chloroplasts, refined through more than a billion years of evolution in plants and algae, act as highly efficient and resilient converters of solar energy. Additionally, these organelles function as complex anabolic factories, synthesizing a wide array of primary and secondary metabolites. The functionality of chloroplasts is dependent on the involvement of more than 3,000 proteins, the majority of which are encoded by the nuclear genome. These nucleus-encoded proteins must cross the chloroplast double lipid membrane to become functional. This translocation process is facilitated by the translocons at the outer and inner envelope membranes of chloroplasts (the outer chloroplast [TOC] and the inner chloroplast [TIC] complexes, respectively) and is driven by an energy-providing motor. Despite decades of research, the composition of these complexes remains highly controversial, especially regarding the TIC and motor components. However, recent studies have provided valuable insight into the TOC/TIC complexes, while also raising new questions about their mechanisms. In this review, we explore the latest advancements in understanding the structure and function of these complexes. Additionally, we briefly examine the processes of protein quality control, retrograde signaling, and discuss promising directions for future research in this field.

Photosynthesis is an essential biological process that occurs within chloroplasts. Recently, Frangedakis et al. (2024) reported that transcription factors- MpRR-MYB2 and MpRR-MYB5 work along with GLK, and also play a role in chloroplast development. The findings from this research could pave the way for engineering crops with enhanced photosynthetic efficiency.

The rhizosphere plays a crucial role in plant growth and resilience to biotic and abiotic stresses, highlighting the complex communication between plants and their dynamic rhizosphere environment. Plants produce a wide range of signaling molecules that facilitate communication with various rhizosphere factors, yet our understanding of these mechanisms remains elusive. In addition to protein-coding genes, increasing evidence underscores the critical role of microRNAs (miRNAs), a class of non-coding single-stranded RNA molecules, in regulating plant growth, development, and responses to rhizosphere stresses under diverse biotic and abiotic factors. In this review, we explore the crosstalk between miRNAs and their target mRNAs, which influence the development of key plant structures shaped by the belowground environment. Moving forward, more focused studies are needed to clarify the functions and expression patterns of miRNAs, to uncover the common regulatory mechanisms that mediate plant tolerance to rhizosphere dynamics. Beyond that, we propose that using artificial miRNAs and manipulating the expression of miRNAs and their targets through overexpression or knockout/knockdown approaches could effectively investigate their roles in plant responses to rhizosphere stresses, offering significant potential for advancing crop engineering.