Current Plant Biology最新文献

Hydroxycinnamates induce lignification in young plants, leading to the overproduction of lignin as a defense mechanism. Phenylpropanoids-containing oligosaccharides are thought to be a signal of pathogen attack on the cell wall polysaccharides. However, it is unclear if hydroxycinnamates induce lignification by acting solely as stress elicitors or feeding the phenylpropanoid pathway as lignin precursors. To examine this hypothesis, we added 1 mM deuterated ferulic acid (FA) or sinapic acid (SA) to the nutrient solution in which we cultivated soybean or maize plantlets. After 24 h, we assessed the biometric parameters and the contents of ester-linked FA and SA, total lignin, monolignol ratio, and heavy monolignols. FA treatment increased the content of ester-linked FA, syringyl, and guaiacyl monomers measured by nitrobenzene oxidation, lignin content, and reduced root growth in both soybean and maize plants. p-Coumaric acid content ester-linked to the cell wall increased in soybean but decreased in maize after treatment with FA. Treatment with SA also induced lignification in soybean but not in maize. SA increased S-lignin and sinapoyl esters content in the cell wall polymers in both soybean and maize. Residues of deuterated hydroxycinnamates were detected in the lignin of both plants in both treatments. The assay demonstrated that exogenously applied SA and FA were metabolized through the phenylpropanoid pathway. Furthermore, they were, at least partially, exported to the apoplast, where they were ester-linked to cell wall polymers. This suggests hydroxycinnamic acids are metabolized differently by plants with different types of cell walls.

Phosphorus (P) is essential for maximizing crop yield, yet many areas dedicated to rice cultivation suffer from a scarcity of plant-accessible inorganic phosphate (Pi) due to its fixation in the soil. Conversely, regions with ample P fertilization often resort to excessive application to compensate for deficiencies, resulting in adverse environmental impacts. While significant strides have been made in understanding the molecular mechanisms governing P uptake capacity (PUP/PAE) and P use efficiency (PUE) in rice, their practical implementation in breeding is impeded by the absence of robust, high throughput phenomics techniques, leading to inconsistencies in gene/quantitative trait loci (QTL) effects. This review underscores the necessity for a comprehensive understanding of Pi transporters, internal Pi remobilization, and root morphology modifications under Pi deficiency, correlating these traits with specific phenotypic markers. Developing precise, cost-effective, high-throughput phenotyping techniques is imperative for creating rice ideotypes with enhanced PAE/PUE. Additionally, we explore the potential of meta-QTL analysis in prioritizing genomic loci related to PUE, utilizing a “meta-genome” encompassing diverse rice reference genomes. We also delve into the potential in the development of phosphite (Phi)-tolerant rice, aiming to reduce dependence on P fertilizers and create herbicide-resistant rice through Phi-based fertilization. Finally, we discuss the utilization of arbuscular mycorrhizal fungi (AMF) to enhance P uptake in rice.

Drought stress, exacerbated by climate change, presents a critical global challenge characterized by increasingly severe and prolonged dehydration events. This phenomenon poses significant obstacles to both agricultural productivity and ecological stability. One promising strategy for addressing this issue involves functional phenotyping, a methodology that provides invaluable insights into the intricate responses of plants to water scarcity. A profound understanding of these responses is crucial for the advancement of drought-tolerant crop cultivars/species, the optimization of irrigation methodologies, and the implementation of effective water resource management practices in agriculture. This review underscores the potential of developing an ideal phenotyping tool that continuously monitors a plant's physiological profile in response to shifting environmental parameters. Such an approach enables the multifaceted characterization and assessment of various functional phenotypes and productivity levels. Through the application of functional phenotyping techniques, we stand to gain invaluable insights into plant behaviour, thereby contributing to the development of drought-tolerant crops and the establishment of sustainable agricultural systems.

Uncaria rhynchophylla (Gouteng), as an evergreen woody vine belong to Rubiaceae family, is a traditional medicinal herb in China. Its terpenoid indole alkaloids (TIAs), which have good antidepressant and combined therapeutic effects on Alzheimer's disease, have attracted widespread attention. However, the content of TIAs is relatively low in U.rhynchophylla, which is unable to meet the growing market demand. The basic helix loop-helix (bHLH) transcription factor family exists in all three eukaryotic kingdoms and can participate in regulating secondary metabolite pathways. So far, there has been no comprehensive analysis of the bHLH gene in U. rhynchophylla, and their role in TIAs is almost unknown. In this study, a total of 171 UrbHLH genes (UrbHLHs) were unevenly distributed on 22 chromosomes and divided into 23 subfamilies. In addition, the physicochemical properties of UrbHLHs were analyzed. Most UrbHLHs in each subgroup had similar gene structures and conserved motifs. Intraspecific collinearity analysis showed that UrbHLH1 may be related to the biosynthesis of TIAs. Subcellular localization experiments revealed that UrbHLH1 is located in the nucleus; Dual luciferase reporter gene analysis (Dual-LUC) showed that UrbHLH1 could activate the expression of UrG10H and Ur10HGO in the TIAs synthesis pathway of U. rhynchophylla. Finally, using yeast one hybrid (Y1H) it was found that the promoter regions of these two genes both have E-box binding elements, which can be bound by UrbHLH1 and produced strong interactions. Therefore, UrbHLH1 may participate in the synthesis of TIAs pathway. In conclusion, this study provides foundation data on the role of UrbHLH transcription factors in regulating TIAs of U. rhynchophylla.

Iron (Fe) deficiency is a pressing global health concern, particularly affecting vulnerable groups like women and children in resource-limited areas. Addressing this challenge requires innovative solutions, and biofortified crops, like Fe-enriched wheat, can offer a sustainable solution to improve nutrition in cereal-based diets. While conventional breeding methods have yielded competitive Fe-biofortified wheat varieties across various nations, the imminent challenges in securing food and nutritional security for the future necessitate a delicate balance: maintaining genetic progress in grain yield while concurrently elevating grain Fe content. Despite substantial strides in elucidating the intricacies of Fe homeostasis, there remains a substantial knowledge gap, especially in the context of wheat and similar crop species. It is paramount to gain a comprehensive understanding of the hurdles impeding Fe enrichment in plant tissues and delve into the diverse mechanisms governing Fe uptake, translocation, transport, and storage within wheat. To surmount these challenges, researchers have explored a multitude of strategies, including mutagenesis, QTL mapping, meta-QTL analysis, GWAS, transgenesis, and genome editing. Furthermore, harnessing the potential of microorganisms, particularly engineered endophytes coupled with plant genes associated with Fe accumulation, emerges as a promising and pragmatic tool for augmenting Fe biofortification in wheat. This comprehensive review underscores the significant advancements made in unravelling the genetic and genomic aspects of Fe accumulation in wheat, while also delineating the future research directions in this field. By synergistically deploying these multifaceted approaches, scientists hold the potential to develop wheat varieties characterized by enhanced grain Fe content, improved bioavailability, and reduced anti-nutritional factors. Such innovations can play a pivotal role in advancing nutrition and health outcomes for populations reliant on wheat-based diets, particularly in resource-scarce regions.

Low light stress seriously affects the growth and yield of crops and the phytohormone brassinosteroid (BRs) plays a vital role in regulating plant adaptation to low light conditions. However, the molecular mechanism underlying this process remains largely unknown. In this study, we showed that exogenous BR effectively alleviated damages to photosynthesis and antioxidant systems, improved the plant biomass under low light stress mimicking treatments in tomato (Lycopersicon esculentum Mill.). Comparative transcriptome profiling analysis revealed that genes related with photosynthesis and Calvin cycle pathways were enriched among the differentially expressed genes (DEG) co-regulated by low light stress and BR. The combination of transcriptome and metabolome analysis showed that BR could mitigate the down-regulation of photosynthesis and Calvin cycle caused by low light stress, and partially restore the up-regulation of Glycolysis / Gluconeogenesis and tricarboxylic acid (TCA) cycle through transcriptional and metabolic reprogramming to alleviate the effects of low light stress. Moreover, we further identified the crucial transcription factors, SIEPR1 and SIERF059, and their potential target genes involved in the regulation of low light stress alleviation mediated by BR signaling. Our results shed new light on the molecular mechanisms underlying the alleviation of low light stress by BR.

Global climate changes have led to severe and frequent drought stress in many areas, seriously threatening the stability of yield in wheat. Exploring the quantitative trait loci for yield stability under drought condition is needed for wheat molecular breeding. In this study, we collected a panel of 432 diverse wheat accessions from different regions around the world and evaluated the drought stress susceptibility index of wheat yield-related phenotypes under drought stress and genotyped the panel with the wheat660K SNP array. Genome-wide association analysis has identified 40 yield stability-related loci, which distribute on various chromosomes. Four loci on Chromosome 1 A, 2B, 3 A and 7B are associate with more than two phenotypic indicators, explaining 1.59% − 8.07% of the phenotypic variation. Among them, Qgns.cas-3A.2 is a novel QTL for wheat yield stability under drought stress. Venn diagram analysis on the drought-responsive expression patterns of Qtgw.cas-3A genes in drought-tolerant and sensitive cultivars, and linkage disequilibrium analysis of the 57Kb region flanking SNP marker AX-108784842 on chromosomes 3 A which displays the highest confidence identified the same candidate gene, which encodes a glycosyl hydrolases family 17 protein. Haplotype analysis indicated that GG allele of this gene is the favorable allele for wheat yield stability under drought. Taken together, these results provide new insights on understanding the genetic basis of wheat yield stability under drought stress and new tools for developing molecular markers to engineer drought-tolerant wheat cultivars.

Catharanthus roseus receptor-like kinase 1-like (CrRLK1L) proteins play important roles in cell growth, plant morphogenesis, reproduction, hormone signaling, plant immunity and stress responses in Arabidopsis. However, not much information is available about their functions in cotton. We identified a total of 125, 73 and 71 full-length putative CrRLK1L genes in G. hirsutum, G. arboreum and G. raimondii, which are much greater than that of the other plants. The phylogenetic and gene structure analysis divided the cotton CrRLK1L genes into six major groups, among which only group I and II contained AtCrRLK1Ls of Arabidopsis. Genome collinearity analysis revealed large scale reciprocal translocations on chromosome 2 among Gossypium A genomes species, which led to uneven distribution of CrRLK1L genes on this chromosome. In addition, transcriptome data combined with qRT-PCR analysis showed some GhCrRLK1Ls were preferentially expressed in fibers during the specific stages of ovules or fibers development. Notably, GhCrRLK1L104 was highly expressed in fibers at 30 days post anthesis, and the GhCrRLK1L104::GFP fusion protein was located on the plasma membrane. Furthermore, overexpression of the GhCrRLK1L104 gene in Arabidopsis increased the trichomes length of the rosette leaves, indicated its vital roles in cell elongation. These results provided a strong foundation to further explore the molecular mechanism of CrRLK1L genes in upland cotton in cell elongation, that can be used in future cotton breeding program.

Chinese cabbage (Brassica rapa subsp. pekinesis) is a vital leafy vegetable crop that thrives within the temperature range of 12 °C to 22 °C. However, high temperatures can adversely impact its growth, development, and yield. To address this issue, we investigated the potential of eugenol and clove essential oil in enhancing stress tolerance in Chinese cabbage. Transcriptome profiling of Chinese cabbage exposed to eugenol, clove essential oil, and heat stress revealed significantly differentially expressed genes (DEGs). Gene set enrichment analysis indicated that treatment with eugenol and clove essential oil significantly influenced defense responses, hormone signaling pathways, and leaf senescence. Additionally, WRKY, ERF, and NAC transcription factors were found to be enriched among the significant DEGs. Notably, eugenol and clove essential oil treatments, as well as exposure to heat stress, were associated with the regulation of leaf senescence. Furthermore, the application of eugenol and clove essential oil mitigated the heat-induced reductions in the contents of chlorophyll a, chlorophyll b, and total chlorophyll in Chinese cabbage. In summary, our findings suggest that eugenol and clove essential oil effectively enhance thermotolerance in Chinese cabbage by modulating leaf senescence and hormone responses.

The colorful “delayed leaf greening” is a common but overlooked phenomenon in phosphorus (P)-limited environments in habitats in tropical, subtropical and temperate forests, but the physiological mechanism underpinning it remains unclear. It is important to understand how allocation of phosphorus to major leaf P fractions shifts during leaf development, as a strategy for utilizing P efficiently. We measured concentrations of leaf nitrogen and P and five chemical P fractions, and eight leaf chemical element concentrations (K, Ca, Mg, Mn, Fe, Cu, Zn and Se) in young and mature leaves of six woody plants exhibiting delayed greening in China. We also measured leaf mass per area, photosynthetic rate, photosynthetic phosphorus-use efficiency, and soil nutrient concentrations. The results indicate six species exhibiting delayed greening had different leaf P concentrations during leaf development, but the same nitrogen concentrations. We further show major leaf chemical P fractions like metabolite P, nucleic acid P and lipid P showed differences in young and mature leaves. The concentration of lipid P, nucleic acid P, Pi and residual P significantly decreased from young to mature leaves, while that of metabolite P was constant. There was a greater allocation of P to phospholipids and metabolite P in mature leaves. The concentration of Cu and K were significantly higher in young leaves. This study provides new insight to investigate the roles of different P fractions in young and mature leaves, and how the allocation shifts for plants to utilize phosphorus.