Journal of Plant Growth Regulation最新文献

Tea plants exposed to temperature stress conditions exhibit reduced quality and yield. Long non-coding RNAs (lncRNAs) are key regulators in temperature stress responses. A genome-wide lncRNA analysis using RNA sequencing data from tea plants under varying temperature stresses was carried out in this study. The analysis identified a total of 23589 putative lncRNAs, with 2483 being differentially expressed (DE). Weighted gene co-expression network analysis (WGCNA) showed 445 DE lncRNAs co-expressed with 544 genes associated to temperature stress responses. Functional annotation indicated that these genes are involved in processes like protein folding, cellular response to decreased oxygen level, response to hypoxia, unfolded protein binding, and response to heat during high temperature stresses; and response to cold, water transport, and water channel activity during low temperature stresses. Additionally, competing endogenous RNA (ceRNA) network analysis revealed 230 temperature-responsive lncRNAs regulating 400 DE genes via 106 microRNAs (miRNAs). To validate high-throughput sequencing data, primers were designed for eight DE lncRNAs, and their expression levels were confirmed. This study enhances understanding of lncRNAs in temperature stress responses, providing a foundation for further research in tea plants.

Acquisition of large-scale phenotyping data are the major bottleneck in associating phenotypic and genotypic data for accurate breeding decisions. High-throughput phenotyping platforms have been developed globally to hasten the next-generation breeding and more sustainable crop production. Phenomics involves collecting non-destructive, extensive, reliable, robust and multi-dimensional data on an organism's phenotype on a large-scale. The success of phenomics is driven by different imaging cameras and techniques like visible light imaging, infrared sensing, fluorescence imaging, 3D imaging, multi and hyperspectral imaging, etc. By utilizing advanced phenotyping platforms and technologies, it is possible to collect vast amounts of data on various aspects of plant growth and development, along with the response to environmental stresses. The phenomics approaches are more efficient based on maximising a plant’s phenotypic expression and differentiation. Throughout the globe, different HTP tools and platforms have been developed to help realize the true potential of breeding programs by bridging the gap between genotype and phenotype, and enhancing the efficiency of selection for maximizing the genetic gain. This review article discusses various platforms and their use in precision phenotyping to accelerate genetic improvement and provides insights into the optimal selection and utilization of HTPs.

UV-B treatment can promote the accumulation of isoflavones in soybeans. This study investigated the possible medium-wave ultraviolet (UV-B) photoreceptor genes in soybeans and the relationship between the UVR8 signaling system and isoflavones synthesis by designing three germination modes. All predicted GmUVR8 were classified into 10 classes (A–J) based on phylogenetic affinities. Isoflavone biosynthesis genes comprising GmCHS, GmCHR1, GmCHI1A, GmCHI1B, GmCHI4A, GmIFS1, and GmIFS2 were activated in response to UV-B treatment, while the corresponding enzyme activities were stably maintained at high levels. The accumulation of total isoflavones was proportional to the time, regardless of the germination pattern. UV-B treatment promoted the accumulation of isoflavones more than white light treatment and the accumulation of all isoflavones except glycitin was promoted by UV-B. The total isoflavones content of soybean sprouts reached a peak under the irradiation intensity of 45 μW/cm² under different irradiation intensities, which increased by 72.65% compared with that in the dark group. Furthermore, the correlation analysis showed that GmUVR8-E, GmUVR8-F₁, GmUVR8-J_1~3, GmUVR8-J₄, and GmUVR8-J_5,6 were highly correlated with isoflavones synthesis and might regulate the transcription of isoflavones synthesis gene, presumed as photoreceptor of UV-B in soybean. The results will provide a scientific basis for developing soybean foods rich in isoflavones.

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Several regulators of phellem/cork formation have been identified in recent years, using mainly transcriptomic approaches. However, this developmental process, showing parallels to the functioning of vascular cambium, remains poorly understood. The cork oak tree (Quercus suber L.) exhibits a remarkable ability to form a traumatic phellogen after debarking, enabling sustainable cork production. We aimed at uncovering post-transcriptional mechanisms controlled by miRNAs, specifically involved in regulating phellogen functioning and phellem differentiation in cork oak. To achieve this, we conducted a comparative analysis of the small RNA transcriptome between differentiating phellem and xylem, both originating from secondary meristems (phellogen and vascular cambium). In addition to identifying miRNAs exclusive to phellogen/phellem tissues, we discovered 246 differentially expressed miRNAs between the two tissues, of which 74 are conserved. The most abundant miRNA families found in phellem tissues were MIR165/166, MIR167, MIR168 and MIR390. By analysing miRNA predicted targets and their expression in the same tissues, many of the differentially expressed miRNAs were found associated with sequence-specific DNA binding functions. Within these, transcription factor families HD-ZIP III, WRKY, NAC and MYB were highlighted as key in phellem differentiation. Furthermore, hormone-mediated signalling pathways, particularly involving auxin, appeared as an enriched biological process, as several ARF transcripts, among other auxin signalling genes like IAA11, ARF18 and ARF19, were identified as putative targets of conserved or novel miRNAs. Overall, our results provide a comprehensive overview of the miRNA landscape during cork formation, providing valuable knowledge for further functional studies and potential practical applications in forest management.

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Saturated vapor pressure deficit (VPD) is plant transpiration’s main driving force and regulates stomatal behavior. In theory, VPD can predict plant transpiration and determine irrigation. Still, the circadian transpiration of plants needs to be clarified for the rapid, short-term response of VPD. Here we set up two VPD environments (low VPD, high VPD) to irrigate three different varieties of tomatoes using our team’s advanced decision irrigation system. The study monitored the diurnal transpiration changes, morphological growth, leaf characteristics, water status, gas exchange, and photosynthesis of the tomatoes. The result showed that when that decision system was used for irrigation, the low VPD environment increased the water potential of roots, stems, and leaves during the daytime, alleviated the hydraulic restriction, and increased the proportion of nighttime transpiration of various tomato varieties. It was likely that the plants changed their circadian transpiration rhythm, and higher stomatal conductance, water use efficiency, and photosynthetic production performance during the daytime were obtained through higher nighttime transpiration. In addition, transpiration showed a response-ability to predict and adjust VPD in advance. There was a very high correlation between environmental factor VPD and plant transpiration during the daytime. Among them, when adding the time lag of −1 h and −0.5 h, the overall decision coefficient R² between the transpiration rate and VPD of each tomato variety was higher than without time delay. We use the daytime transpiration data of 30 min as fitting examples. The decision coefficients between transpiration and VPD accumulation within 30 min were 0.90, 0.81, and 0.89, respectively. But this correlation was insignificant at night. This study provided a new idea for the real-time and accurate prediction of irrigation for protected tomatoes using transpiration decisions.

CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION-related) peptides are systemic regulators of legume-rhizobium symbiosis that negatively control the number of nitrogen-fixing nodules. In Medicago truncatula, the expression of the MtCLE35 gene is activated in response to rhizobial inoculation and nitrate treatment, and its overexpression systemically inhibits nodulation. However, little is known about the molecular mechanisms underlying MtCLE35-mediated inhibition of nodulation. In order to elucidate target genes regulated by the MtCLE35-induced signaling cascade, we analyzed the transcriptome of MtCLE35-overexpressing roots inoculated by rhizobia using MACE (Massive Analysis of cDNA Ends) sequencing. Totally, 1390 genes were found to be differentially expressed between MtCLE35-overexpressing (35S::MtCLE35) and control (35S::GUS) roots after rhizobial inoculation, among them 268 genes were upregulated and 1122 genes were downregulated. Among downregulated genes, many known regulators of legume-rhizobia symbiosis were found. Genes upregulated in rhizobia-inoculated MtCLE35-overexpressing roots included ones associated with defense response and cellular redox status. Furthermore, stable transgenic plants overexpressing the MtCLE35 gene were obtained in this study, and gene expression qPCR analysis of selected differentially expressed genes in rhizobia-inoculated roots was performed in such plants. Collectively, our data suggest that overexpression of the MtCLE35 gene prevents the induction of nodulation program, which is accompanied by the expression of defense-related gene in MtCLE35-overexpressing rhizobia-inoculated M. truncatula roots.

The commercial seaweed Gracilariopsis lemaneiformis is mainly used as raw material for agar production and feed for abalone. The heat-resistant strains G. lemaneiformis are extensively cultivated in the northern and southern coasts of China, yet high temperature in the summertime in southern coasts has hindered the growth and limited the cultivated periods of this seaweed. A vast majority of reports have manifested that exogenous phytohormone brassinosteroids (BRs) can improve the plant heat-tolerance. However, little is known about the effect and its underlying mechanism of BRs in algae. In this study, the effect of 24-epibrassinolide (EBR) on the physiological and transcriptional levels was investigated in the high-temperature stressed G. lemaneiformis. Physiological data indicated that EBR application could improve the growth with 1.43-fold on day 5 and non-photochemical quenching parameter, reduce the productions of reactive oxygen species (ROS) and malondialdehyde (MDA), enhance the accumulations of proline, trehalose, and the levels of endogenous 2-methylthio-N6-isopentenyladenine (2MeSiP), 2-methylthio-cis-zeatin riboside (2MeScZR), jasmonic acid (JA), N-[(-)-jasmonoyl]-(l)-phenylalanine (JA-Phe) and salicylic acid 2-O-β-glucoside (SAG) under high-temperature condition. In addition, transcriptomic analysis identified 656 upregulated- and 680 downregulated-genes following the EBR treatment compared to the control group, revealed that EBR activated the metabolic pathways of the glycolysis, tricarboxylic acid (TCA) cycle, pentose phosphate pathway, and synthesis of threonine, methionine, and serine. Taken together, the aforementioned results highlighted the beneficial effect of EBR via alleviating the oxidative stress, promoting the accumulations of osmolytes and stress-related phytohormones, and activating the metabolisms of carbohydrate and amino acid, thereby resulting in the mitigating of growth inhibition by high-temperature stress in G. lemaneiformis.

Abscisic acid (ABA) is a phytohormone that occurs in plants at very low concentration (pmol/g fresh weight) and regulates multiple biological processes, including stomatal closure, seed germination, and responses to environmental stresses. In the present study, isolation of ABA, ABA glucosyl ester, and 11 ABA amino acid conjugates from minute quantities of plant tissue (less than 20 mg fresh weight) was achieved using a purification method based on the combination of an Oasis HLB column and an immunoaffinity sorbent. New monoclonal antibodies raised against (+)-cis,trans-ABA conjugated to BSA through its carboxyl group (C1) were characterised by enzyme-linked immunosorbent assay (ELISA) and used for immunoaffinity chromatography (IAC) gel preparation. The use of immunoaffinity purification significantly reduced matrix effects and increased the selectivity and sensitivity of subsequent UHPLC-MS/MS analysis. In addition to (+)-cis,trans-ABA and its glucosyl ester, a new abscisic acid conjugate, ABA-L-glutamate, was isolated by IAC and identified by tandem mass spectrometry in pea (Pisum sativum L.), Lepidium sativum L. and wheat (Triticum aestivum L.) seedlings. However, it was not found in 10-day-old seedlings of Arabidopsis thaliana or water-stressed tobacco (Nicotiana tabacum L.) leaves. Here, the identification of an ABA conjugate with glutamic acid in plants is described for the first time.

Postharvest senescence presents a formidable obstacle to the economic viability of cut flowers, necessitating meticulous preservation strategies within the cut flower industry. This study meticulously examines the efficacy of exogenously applied proline in enhancing floral longevity in Ranunculus asiaticus cut flowers, while also exploring the underlying physiological and biochemical mechanisms. Floral buds harvested at the half-open stage, were systematically allocated to five clusters for experimentation. The cluster of flowers specified as control was held in distilled water, whereas rest of the clusters received varying concentrations of proline (2 mM, 4 mM, 6 mM and 8 mM). Remarkably, the application of 6 mM proline proved most effective, significantly extending flower lifespan by approximately four days compared to the control. This longevity enhancement correlated with notable increases in floral diameter, soluble proteins, sugars and phenols. The findings indicate a pivotal role of exogenous proline in alleviating oxidative stress within petal tissue, as evidenced by reduced lipoxygenase activity and enhanced antioxidant enzyme activity. Furthermore, a decrease in lipid peroxidation was observed alongside heightened membrane stability, as measured by the membrane stability index. Conclusively, proline treatment emerged as a promising postharvest intervention in enhancing longevity of Ranunculus asiaticus flowers by modulating underlying biochemical mechanisms.

Soil salinization is a major abiotic stress that significantly impairs plant growth and development. This leads to various physiological disorders in plants, ultimately posing a threat to global food security. Polyamines are emerging as new plant growth regulators that can help promote salt stress tolerance in plants. Research has shown that application of polyamines, which are organic compounds containing multiple amine groups, can help alleviate the detrimental effects of salt stress on plants. Increasing the levels of polyamines, either naturally during salt stress or through exogenous application, helps establish homeostasis of polyamines within the plant. This polyamine homeostasis then leads to the homeostasis of reactive oxygen species (ROS) through several physiological processes such as hormonal regulation, ion channel regulation, activation of ROS scavenging enzymes, and antioxidant activity. Collectively, these polyamine-mediated physiological changes help the plant establish ROS homeostasis, which is a key mechanism underlying enhanced salt stress tolerance. The balanced regulation of polyamines and ROS is crucial for plant adaptive responses and survival under saline conditions. Overall, the use of polyamines represents a promising approach for developing more salt-tolerant crops and improving agricultural productivity in saline-affected regions.