Plant signaling & behavior最新文献

Polygonatum sibiricum Red, known as Huangjing in Chinese, is a perennial plant valued in traditional Chinese medicine and is a nutritional food ingredient. With increasing market demand outpacing wild resource availability, cultivation has become essential for sustainable production. However, the cultivation of P. sibiricum is challenged by the double dormancy characteristics of seeds, which include embryo and physiological dormancy. This affected the germination of seeds and the establishment of seedlings. This study investigates the role of plant hormones in breaking seed dormancy and regulating germination and emergence in P. sibiricum. We found that cold stratification at 4°C for over 70 d significantly alleviates seed dormancy, associated with changes in endogenous hormone levels. Auxin, gibberellin, abscisic acid, cytokinin, salicylic acid, jasmonic acid, and ethylene were identified as key players in these processes. Exogenous applications of GA3 and 2-coumarate (2-hydroxycinnamic acid) significantly enhanced seed germination, while 6-BA and GA3 promoted corm growth and development. In conclusion, our research provides insights into the hormonal regulation of seed dormancy and germination in P. sibiricum, offering valuable strategies for improving cultivation practices. Further studies are needed to explore the specific mechanisms of hormone interactions and to develop optimized germination and seedling establishment strategies for this medicinally important plant.

Chenopodium ficifolium is a close diploid relative of the tetraploid crop Chenopodium quinoa. Owing to its reproducible germination and seedling development, it becomes a promising model for studying floral induction, providing a basis for the comparison with C. quinoa. Two C. ficifolium genotypes differ in photoperiodic requirement: C. ficifolium 283 accelerates flowering under long days, whereas C. ficifolium 459 flowers earlier under short days. This study conducted a comprehensive transcriptomic and hormonomic analysis of floral induction in the long-day C. ficifolium 283 and compared the findings to previous experiments with the short-day C. ficifolium. Phytohormone concentrations and gene expression profiles during floral induction were largely similar between the two genotypes. However, a subset of genes exhibited contrasting expression patterns, aligning with the genotypes' differing photoperiodic requirements. These genes, predominantly homologs of flowering-related genes in Arabidopsis thaliana, were activated under long days in C. ficifolium 283 and under short days in C. ficifolium 459. Notably, the contrasting expression of the FLOWERING LOCUS T-LIKE 2-1 gene, which was previously shown to induce precocious flowering in A. thaliana, confirmed its role as a floral activator, despite its low expression levels.

The growth state of pepper plants under different soil conditions under drought stress was studied, using RGB decomposition, thermal infrared imaging, plant electrical signal and electrochemical fingerprinting. Since porous biochar can trap more water, plants in a soil-biochar environment grow better than those in the original soil. With the increase of biochar concentration, there are more pixels in the visible image of plants, and the surface temperature of plants is lower. Biochar can also provide a stable electrochemical environment. With the increase of biochar concentration in soil, the electrical signal amplitude of pepper plants decreased and the concentration of electrochemical substances increased.

Auxin-induced xylem formation in angiosperms is negatively regulated by thermospermine, whose biosynthesis is also induced by auxin. In Arabidopsis thaliana, loss-of-function mutants of ACL5, which encodes thermospermine synthase, exhibit a dwarf phenotype accompanied by excessive xylem formation. Studies of suppressor mutants that recover from the acl5 dwarf phenotype suggest that thermospermine alleviates the inhibitory effect of an upstream open-reading frame (uORF) on the main ORF translation of SAC51 mRNA. Many suppressor mutations for acl5 have been mapped to the uORF conserved in the SAC51 family or to ribosomal protein genes, such as RPL10A, RPL4A, and RACK1A. In this study, we identified newly isolated acl5 suppressors, sac501, sac504, and sac506, which are additional alleles of RPL10A and the uORFs of SAC51 family members, SACL1 and SACL3, respectively. To investigate whether acl5-suppressor alleles of ribosomal genes broadly affect translation of uORF-containing mRNAs, we examined GUS activity in several 5'-GUS fusion constructs. Our results showed that these alleles enhanced GUS activity in SAC51 and SACL3 5'-fusion constructs but had no effect on other 5'-fusion constructs unrelated to thermospermine response. This suggests that these ribosomal proteins are specifically involved in the thermospermine-mediated regulation of mRNA translation.

Maize (Zea mays L.) is a vital crop worldwide, serving as a cornerstone for food security, livestock feed, and biofuel production. However, its cultivation is increasingly jeopardized by environmental challenges, notably soil salinization, which severely constrains growth, yield, and quality. To combat salinity stress, maize employs an array of adaptive mechanisms, including enhanced antioxidant enzyme activity and modulated plant hormone levels, which work synergistically to maintain reactive oxygen species (ROS) balance and ion homeostasis. This review explores the intricate interactions among ROS, antioxidant systems, plant hormones, and ion regulation in maize under salt stress, providing a comprehensive understanding of the physiological and molecular basis of its tolerance. By elucidating these mechanisms, this study contributes to the development of salt-tolerant maize varieties and informs innovative strategies to sustain agricultural productivity under adverse environmental conditions, offering significant theoretical insights into plant stress biology and practical solutions for achieving sustainable agriculture amidst global climate challenges.

Arbuscular mycorrhizal fungi (AMF) are crucial components of the soil microbiomes that establish symbiotic associations with most terrestrial plants. The review summarizes the basic mechanisms behind the plant-AMF symbiosis, the genes involved in the fungal and their plant counterparts, novel biomolecules and growth regulators, leading to probable signal transduction pathways. It also focuses on the involvement of lipids and strigolactones in establishing AMF-plant symbiosis. Herein, we further emphasize the role played by these AMF in enhancing plant resistance to various abiotic stresses while giving a broad outline of current research practices and attempting to dissect the mechanism behind the AMF-mediated abiotic stress signal transduction. Discussion on the mechanisms behind this stress reduction involving AMF will be valuable for the researchers, agronomists, and environmentalists involved in sustainable agriculture. Water scarcity, salinity, heavy metals, and extreme temperatures are the primary abiotic stresses that pose serious challenges to agricultural sustainability and ecosystem functioning. Conventional responses to such pressures typically rely on genetic modifications as well as chemical treatments, which could be expensive and detrimental to the environment. However, these AM fungi act in an alternative way that is natural and cost-effective too, leading to healthy plants with resilience toward stress through symbiosis, leading to the fulfillment of the United Nations Sustainable Development Goal (UNSDG) 2 of zero hunger.

Aims: Analyzing the rhizosphere microbial community structure of Atractylodes chinensis from different regions and its correlation with the accumulation of main medicinal active ingredients, this study aims to explore the impact of rhizosphere soil microorganisms on the effective components of A. chinensis, providing a scientific basis for the high-quality and high-yield cultivation of A. chinensis.

Methods and results: The rhizosphere soil of three-year-old A. chinensis was used as the research object. High-throughput sequencing technology was employed to analyze the rhizosphere bacterial and fungal community structures. High Performance Liquid Chromatography (HPLC) was used to detect the contents of atractylodin, atractylon, β-eudesmol, and atractylenolide III in the medicinal materials. Pearson correlation analysis was performed to explore the relationship between soil microbial communities and the active ingredients. α-diversity results showed that the Yaowangmiao village (YWM) microbial community had the highest richness and diversity, while Xingzhoucun (XZC) had the lowest, and Beiwushijiazi village (BWSJZ) had the lowest fungal community diversity and richness. PCoA analysis at the phylum level indicated that soil bacterial communities were more dispersed than fungal communities among different regions. The bacterial community in XZC significantly differed from other regions, while fungal communities in BWSJZ and Ximiaogong village (XMG) showed considerable differences from other regions. The content of active ingredients in different regions showed that Yuzhangzi village (YZZ) and BWSJZ had higher content and better quality of medicinal materials according to the content of atractylodesin specified in the Chinese Pharmacopoeia Commission. The dominant bacterial phylum in the rhizosphere soil of YZZ was Acidobacteriota, and the dominant genus was RB41. In BWSJZ, Acidobacteriota was the dominant bacterial phylum, with Arthrobacter and unclassified_f_Vicinamibacteraceae as dominant genera; the dominant fungal phylum was Basidiomycota, with Tausonia as the dominant genus. Different bacterial and fungal communities synergistically promoted or inhibited the synthesis of four active ingredients.

Conclusion: In short, this provides a theoretical basis for the distribution of soil rhizosphere microbial communities in the cultivation of A. chinensis and offers a reference for the cultivation of A. chinensis medicinal materials.

Neighboring plants exchange adaptive information related to their genetic identity, stress experiences, and reproductive state. Here, we tested the possibility that Plantago asiatica plants utilize both above- and below-ground communication to differentially respond to stress cues perceived from neighbors with variable genetic identities. Stress response was observed by recording stomatal aperture in stressed plants and their neighbors while restricting interplant communication to either root or shoot cueing. Split-root plants were planted in triplets at equidistant intervals. Half of the roots of the central plant were subjected to salt stress, while the other half shared its rooting volume with the roots of an unstressed neighboring plant on one side, and its headspace with another unstressed neighbor on the other side. Sixty minutes after the onset of salt stress, soil-sharing neighbors had a larger proportion of closed stomata when the stressed plant was genetically closer (sibling [SB] or from a near population [NP]) than from a more remote population (FP). In contrast, aboveground stress cueing was equally effective regardless of the genetic relatedness of the neighboring plants. The findings demonstrate for the first time a concurrent utilization of both specific and nonspecific interplant stress cueing. The results call for further investigation into the adaptive implications of these communication modes on the survival and performance of P. asiatica under variable environmental scenarios.

GRAS proteins represent a unique class of transcription factors that are exclusive to plants. Among the various subfamilies within the GRAS family, the phytochrome A signal transduction 1 (PAT1) subfamily is particularly prominent, given its multifaceted regulatory functions in phytochrome signaling pathways and stress response mechanisms, as well as its involvement in plant developmental processes. Despite the recognized importance of GRAS proteins, there are no studies to date that have characterized the GRAS gene family in Medicago edgeworthii. In this study, we performed a comprehensive genome-wide analysis of GRAS genes and identified nine genes belonging to the PAT1 subfamily in M. edgeworthii. Multiple sequence alignment of these proteins revealed the presence of a conserved C-terminal GRAS domain, alongside a highly variable N-terminal region. Additionally, we observed that members of the PAT1 subfamily were expressed in roots, stems, and leaves, indicating their broad involvement in the development of various tissues in M. edgeworthii. Furthermore, functional analysis indicated that PAT1 subfamily proteins in M. edgeworthii activated the expression of MeDOF3.4 gene, indicating that PAT1 subfamily proteins may be associated with the promotion of cell proliferation and graft fusion. In conclusion, this study provided the first comprehensive characterization of PAT1 subfamily genes in M. edgeworthii, establishing a foundation for future research on the functional roles of MeGRAS genes and providing a theoretical basis for the development of high-quality Medicago varieties.

The most damaging disease affecting citrus globally is Huanglongbing (HLB), primarily attributed to the infection by 'Candidatus Liberibacter asiaticus' (CaLas). Based on comparative transcriptome data, two cellulose synthase (CESA) genes responsive to CaLas infection induction were screened, and one gene cloned with higher differential expression level was selected and named CsCESA1. we verified the interaction between CsCESA1 and citrus exopolysaccharide 2 (CsEPS2) proteins. Subcellular localization in tobacco indicated that both CsCESA1 and CsEPS2 proteins are primarily located in the nucleus and cytoplasm. RT-qPCR analysis indicated that the expression levels of CsCESA1 and CsEPS2 were associated with variety tolerance, tissue site, and symptom development. Furthermore, we generated CsCESA1 and CsEPS2 silencing plants and obtained CsCESA1 and CsEPS2 silencing and overexpressing hairy roots. The analysis of hormone content and gene expression also showed that CsCESA1 and CsEPS2 are involved in transcriptional regulation of genes involved in systemic acquired resistance (SAR) response. In conclusion, our results suggested that CsCESA1 and CsEPS2 could serve as potential resistance genes for HLB disease, offering insights into the plant's defense mechanisms against HLB.