Planta最新文献

Main conclusion: Alternative splicing (AS) which increases the diversity of the transcriptome frequently occurs in plants following stress treatment. Transcripts from AS offer potential for designing more resilient crops. Rapid advances in technology on full-length transcriptome sequencing (e.g. long-read single-molecule real-time), high-throughput RNA sequencing, direct RNA-sequencing platforms and high-throughput analysis have provided rapid characterization of transcriptomes with frequent encounters of alternative splicing (AS) in plants, particularly following biotic and abiotic (heat, low temperature, drought, lead and salt) stress treatments. Comprehensive plant databases of stress-responsive AS events, including those from Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), indicate that intron retention is most prevalent. Given that plants are sessile, AS allows the plant to diversify its transcriptomic and proteomic landscape to enhance stress protection. Sometimes, the overexpression of a splice variant in transgenic plants will result in protection against the AS-triggered stress. Recent examples of stress-related AS in plants will be discussed together with the potential of splice variants in designing more resilient crops to thwart climate change, improve productivity and enhance food security.

Main conclusion: Cultivation medium affects apoplastic root barrier formation, gene expression, and morphology across crops, showing that soil growth compared to hydroponics strengthens suberization and lignification while altering plant structural traits. Hydroponic cultivation is commonly used in plant physiology studies; however, studies involving soil are rare. The response of 3 monocotyledonous and 3 dicotyledonous species to cultivation in soil compared with that to cultivation in hydroponic solution was investigated along with the quantification of relevant morphological parameters. The root anatomy was studied with the help of histochemical and microscopic analyses. Root suberin and lignin content were quantified via gas chromatography and mass spectrometry. Transcriptional changes were assessed via RNA-Seq analyses which compared the two growth conditions of barley plants. The results revealed that the plants of all the species cultivated in soil presented significantly longer roots and higher suberin and lignin contents. The above-ground organs of the plants grown in the hydroponic solution presented greater biomass accumulation, with greater shoot dry weights and leaf surface areas. We conclude that across a range of crop genera, the different physicochemical characteristics of the two cultivation media have a pronounced influence on plant morphology, root system architecture, and apoplastic barrier formation.

Main conclusion: HSP101 from IR64 (indica) rice is more effective at resolving protein aggregates in yeast as compared to Nipponbare (japonica). A newly developed dCAPS marker can distinguish polymorphism in HSP101 coding region. Rice is a staple crop that feeds more than 50% of the world's population and heat stress significantly impacts its yield. The heat shock protein ClpB1/HSP101 plays a crucial role in the survival of plants under heat stress. We have recently reported HSP101 polymorphism between two Asian rice subspecies indica and japonica by examining the 3K rice genomes. Here, we confirm the polymorphism by resequencing HSP101 and report the functional significance of HSP101 polymorphism during heat stress by expressing the protein coding regions of HSP101 from IR64 (indica) and Nipponbare (japonica) rice types in yeast and Arabidopsis thaliana. For transformation in Arabidopsis, we used the constitutively expressing 2XCaMV35S promoter to drive the expression in the trans-hosts. Variable HSP101 expression levels occurred in the transformed Arabidopsis progenies and, as a result, we could not note a clear-cut differential response of the two forms in providing heat tolerance to transformed plants. Using a heat-inducible yeast HSP104 promoter, we expressed two isoforms of HSP101 in yeast cells containing GFP-tagged RNQ prion. The RNQ-GFP aggregation was reduced to a significantly higher extent in yeast cells expressing the IR64 HSP101 compared to the yeast cells transformed with Nipponbare HSP101. We developed a dCAPS marker to distinguish the indica and japonica HSP101 alleles.

Main conclusion: TaHSFC3B enhanced the drought tolerance of overexpressed Arabidopsis and decreased the drought tolerance of wheat silenced plants by participating in ROS scavenging and ABA pathway. Heat shock transcription factors (HSFs) have extraordinary significance in plants' response to abiotic stress. But the specific function and mechanism of HSF in imparting drought resistance to wheat remain unclear. In this study, RT-qPCR and GUS staining suggested that the expression abundance of wheat HSF TaHSFC3B was high in grains, leaves, roots, and stems, and could be induced by PEG 6000 and abscisic acid (ABA). Subcellular localization displayed that the fluorescence signal of TaHSFC3B appeared in the nucleus, and transcriptional activation analysis indicated that full-length TaHSFC3B had no transcriptional activation activity. Overexpression of TaHSFC3B in Arabidopsis enhanced drought resistance by regulating the reactive oxygen species (ROS) and ABA pathways displaying improved antioxidant capacity, increased ABA accumulation and hypersensitivity, ultimately leading to reduced stomatal opening, higher leaf water content, elevated leaf temperature, and decreasing the survival rate under high temperature. In the transgenic Arabidopsis lines, the expression levels of genes associated with ROS and ABA pathways were significantly upregulated. In contrast, the silencing of TaHSFC3B in wheat resulted in a diminished antioxidant capacity and a reduced ABA accumulation, and subsequently led to reduced drought resistance, which specifically manifested as enlarged stomatal opening, increased leaf water loss, decreased temperature of detached leaves. TaHSFC3B silencing also significantly reduced the expression abundance of genes related to ROS and ABA pathways. This study provides important scientific support for a deeper understanding of the key functions of HSF and their potential applications in drought-resistant breeding, promoting the integration of research on plant stress tolerance mechanisms with practical breeding.

Main conclusion: This study unravels the function of SmMYC2 regulating resistance to B. cinerea in S. miltiorrhiza. Salvia miltiorrhiza is a traditional medicinal herb and commonly used to treat cardiovascular and cerebrovascular diseases. Gray mold caused by Botrytis cinerea poses a significant threat to production of many medicinal plants. The key transcription factor SmMYC2 has been found to contribute to promoting the biosynthesis of tanshinones or phenolic acids, and also mediated salt resistance in S. miltiorrhiza. However, limited information underlying its role of resistance to B. cinerea is available. In this study, simultaneous improvement of tanshinone and phenolic acid biosynthesis was observed in transgenic S. miltiorrhiza plants overexpressing SmMYC2 (OE-SmMYC2). Besides, expression pattern analysis revealed that SmMYC2 transcript increased significantly after B. cinerea infection. OE-SmMYC2 plants significantly improved their resistance to B. cinerea, and enhanced the expression level of the defense marker genes, such as SmPR1, SmPR10, SmSam a1, and SmPR-STH2. Besides, three antioxidant enzymes including catalase, peroxidase and superoxide dismutase were increased in OE-SmMYC2 lines, and SmMYC2 reduced the H₂O₂ accumulation. Overall, our results revealed that SmMYC2 played positive regulatory roles in resistance to B. cinerea in S. miltiorrhiza.

Main conclusion: Gibberellins promote differentiated root and shoot responses in growth, morphology, and carbon allocation. Gibberellins (GAs) are plant hormones that are produced in young tissues and organs, acting locally in growing shoots and roots or being transported to other organs. The role of GAs in root development was first investigated decades ago using plants severely deficient in GA biosynthesis. However, only few studies have examined root metabolism in plants with reduced GA levels and evaluated its association with root growth and morphology. Furthermore, the signaling between the root and shoot systems plays a key role in coordinating plant growth and development. Therefore, this study aimed to assess the impact of endogenous alterations in GA levels on tomato mutants exhibiting mild (gibberellin deficient-3, gib3), intermediate (gib2), and high (gib1) GA deficiency on root and shoot growth, morphology, respiratory metabolism, and labeled carbon allocation. The low GA content exerted an effect on shoot growth and morphology, which, surprisingly, led to minor changes in the mutant roots. The gib2 and gib1 mutants exhibited higher proportions of thick roots than the wild-type and gib3, but the growth of roots with smaller diameters was most pronounced in these genotypes. The carbohydrate oxidation was influenced by a reduction in GA biosynthesis within mutant leaves and roots. In addition, the differential sensitivity to GA by each organ likely contributed to variations in sugar accumulation. Together, these results indicate that shoot tissues exhibit a distinct response compared to root tissues, suggesting a decoupling of root growth and carbon allocation from shoot growth and development in GA-deficient plants. This observation points to a key role for GA in orchestrating the growth of both shoots and roots.

Main conclusion: Inoculation with Pseudomonas simiae WCS417 improves cucumber growth under Fe deficiency conditions and induces iron-deficiency responses, making it a promising candidate for sustainable biofertilization strategies in dicot plants. Iron (Fe) deficiency poses a significant agronomic challenge in calcareous soils, particularly affecting dicot plants. Conventional production methods rely heavily on high-yielding varieties and the application of substantial amounts of agrochemicals, leading to considerable environmental concerns. In this context, leveraging the potential of beneficial rhizosphere microorganisms as biofertilizers represents a highly promising and environmentally sound alternative to chemical fertilizers. This study aims to investigate the efficacy of the nonpathogenic strain Pseudomonas simiae WCS417 in eliciting Fe deficiency responses in cucumber plants, along with its impacts on plant growth and Fe chlorosis. Conducted under hydroponic conditions, our experiments reveal compelling outcomes. Root inoculation of cucumber plants with P. simiae significantly enhances plant growth while concurrently mitigating Fe chlorosis symptoms over successive cultivation days. The inoculation with this bacterium induces acidification in the subapical zone of cucumber roots, facilitating Fe solubility in the rhizosphere. Additionally, P. simiae triggers the upregulation of Fe-related genes in inoculated plants, even under Fe sufficiency. In conclusion, P. simiae emerges as a potent enhancer of Fe deficiency responses in cucumber plants. Its ability to promote growth, enhance Fe solubility through rhizosphere acidification, and alleviate Fe chlorosis underscores its potential as an effective biofertilizer for a sustainable Fe nutrition of dicot plants.

This study aims to elucidate the mechanisms of carbon metabolism regulation involved in the solidification of bamboo culms in Phyllostachys heteroclada f. solida. Differentially expressed genes (DEGs) between Ph. heteroclada f. solida and hollow-stemmed variant Ph. heteroclada were identified by transcriptome sequencing. Enrichment analysis of GO and KEGG pathways revealed pronounced divergence in starch-sucrose metabolism and phenylpropanoid biosynthesis pathways. Key starch enzyme genes (e.g., PYG and AMY) were downregulated, while genes involved in sucrose metabolism (e.g., INV and SUS) were upregulated in Ph. heteroclada f. solida. Concurrently, lignin biosynthesis genes (e.g., PAL, C4H, and 4CL) were downregulated, whereas genes associated with cell wall synthesis substances such as pectin and cellulose were upregulated. Non-structural carbohydrate accumulation in Ph. heteroclada f. solida was consistent with these gene expression patterns. The study identified key differences in carbon metabolism pathways between Ph. heteroclada f. solida and Ph. heteroclada, demonstrating that the regulation of carbon metabolism genes plays an important role in culm solidification. These findings provide a foundational understanding of the molecular mechanisms underlying bamboo stem variation and offer insights for future bamboo breeding efforts.

Main conclusion: Hydrogen cyanide (HCN) is a ubiquitous gasotransmitter essential for regulating ROS metabolism and cellular redox balance. This modulation plays a crucial role in metabolic processes in higher plants and animals, highlighting HCN's importance in cellular signalling and stress response. Hydrogen cyanide (HCN) is synthesised in plants and animals and present ubiquitously in the environment. It is considered to be a gasotransmitter and is proposed to play a fundamental role in the origin of life. At concentrations higher than 100 µM, HCN is highly toxic to most aerobes, but at lower concentrations (below 100 µM) it serves as a signalling molecule in plants. The importance of this molecule in plant metabolism is highlighted by the fact that all higher plants produce HCN via various pathways. Given its toxicity, plants frequently store HCN as conjugates with sugars or lipids in vacuoles. HCN modulates the metabolism of reactive oxygen species (ROS), and this is also linked to the disruption of electron flow in the mitochondrial respiration chain. ROS are signalling compounds acting together with hormones in regulation of many physiological processes and typically modify the activity of enzymatic antioxidants by altering ROS levels, thereby impacting cellular redox potential. The aim of this review, therefore, is to describe the relationship between HCN activity and ROS metabolism, with a focus on higher plant systems in particular.

Main conclusion: Experimental transplantation of microspores and manipulation of locular fluid, in vivo, confirm a complex interplay between physicochemical processes and gene expression in shaping the 3-D ultrastructure of the developing exine. We aimed to understand the underlying mechanisms of development of the exine, the outer layer of the pollen wall, one of the most complex cell walls in plants. Control of the processes involved remained obscure until it became clear that the stages observed coincided, in essence, with the sequence of micellar self-assembling mesophases. To test this, a series of in vitro experiments were undertaken earlier (Gabarayeva et al., Ann Bot 123:1205-1218, 2019;Gabarayeva et al., New Phytol 225:1956-1973, 2020), in which exine-like patterns were generated in colloidal mixtures by self-assembly, without any genomic participation. The results of those experiments, carried out "in a vial", have shown that physicochemical interactions, phase separation and self-assembly are capable of generating exine-like patterns. The aim of the new experiments described here, conducted in living plants, was to alter the environment within the anther locule, observing any effects on the processes of exine ontogeny, and to see whether physicochemical interactions play the important role, suggested by in vitro experiments. In the first experiment, early microspore tetrads of Borago officinalis were transplanted into the anthers of Cucurbita maxima. In the second experiment, a surfactant mixture was injected into Cucurbita anthers to alter the environment of self-assembly. After several days, anthers were fixed and studied with TEM. The results confirm our earlier finding from in vitro studies, that-although gene expression in developing microspores and the anther is of fundamental importance-physicochemical forces also play a significant role in exine development. It is the interplay between controls that underpins the vast morphological diversity observed in sporoderms.