Physiologia plantarum最新文献

Pigeon pea is an important economic crop with medicinal and nutritional value. Unfortunately, pest infestation of leaves during postharvest storage seriously affects the quality of pigeon pea. Phytohormones play a crucial role in disease and pest defence by regulating the accumulation of specialized metabolites. Still, their impact on the postharvest storage of pigeon pea has not been reported. In this study, the physiological parameters and main phenotypes of pigeon pea leaves treated with MeJA, ABA, and GA were investigated for the first time. The activity of the antioxidant enzyme system, which eliminates reactive oxygen species, was enhanced by applying MeJA, GA, and ABA. MeJA, GA, and ABA significantly affected crown width, plant height, and relative water content in pigeon pea, respectively. Metabolomic profiling analysis identified phenolic compounds as the main differentially accumulated metabolites (DAMs). UPLC-QqQ-MS/MS identified stilbenes, flavanones, flavones, isoflavones and anthocyanins as major phenolic compounds responsive to MeJA, GA, and ABA induction. By feeding insects, it was found that the insects fed on MeJA-, ABA-, and GA-treated leaves less than on control leaves. Correlation analysis confirmed that isoflavones play an important role in this process. Moreover, the expression of key genes involved in flavonoid biosynthetic pathways and anti-insect-related genes was regulated by MeJA, GA, and ABA. Overall, this work provides a new strategy for the cultivation and storage of pigeon pea or other commercial crops and preliminarily clarifies that flavonoid metabolites under plant hormone treatment can promote plant growth and defence against insects by regulating reactive oxygen species.

In this research, we analyzed Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeats (ISSR) and Sequence-related amplified polymorphism (SRAP) markers to evaluate the genetic diversity of eighteen different onion genotypes with various resistant levels to FOC. The results showed that the polymorphism means between RAPD primers was 61.11 to 81.81%; ISSR primers, 62.50 to 81.81%; and SRAP primers, 56.25 to 76.25%. Overall, by assessing MI, PIC, I and H indices, indicating the best thrive in evaluating the genetic diversity of the related onion populations. There is a significant correlation between the generated dendrograms based on similarity matrices. The classification pattern in dendrograms shows a corresponding correlation with the FOC disease severity bunches. So in all three markers studied, 'Saba' and 'Saba - HS', the most resistant ones to FOC disease, were grouped in a branch, and the 'Sahar - HS' and 'Golden Eye', the most susceptible ones were also grouped in another branch separately. This finding indicates that predominant primers act as markers linked to resistance gene(s) against FOC, which can be used to select onions resistant to FOC disease in any breeding scheme.

Nitrogen (N) is a crucial macronutrient for plant growth, with nitrate as a primary inorganic N source for most plants. Beyond its role as a nutrient, nitrate also functions as a signalling molecule, influencing plant morphogenetic development. While nitrate utilization and signalling mechanisms have been extensively studied in model plants, the origin, evolution, and diversification of core components in nitrate uptake, assimilation, and signalling remain largely unexplored. In our investigation, we discovered that deep sea algae living in low nitrate conditions developed a high-affinity transport system (HATS) for nitrate uptake and a pathway of nitrate primary assimilation (NR-NiR-GS-GOGAT). In contrast, low-affinity transport systems (LATS) and the plastid GS originated from the ancestors of land and seed plants, respectively. These adaptations facilitated amino acid acquisition as plants conquered terrestrial environments. Furthermore, the intricate nitrate signalling, relying on NRT1.1 and NLP7, evolved stepwise, potentially establishing systematic regulation in bryophytes for self-regulation under complex terrestrial nitrate environments. As plants underwent terrestrialization, they underwent adaptive changes to thrive in dynamic nitrate environments, continually enhancing their nitrate uptake, assimilation, and signal transduction abilities.

The use of stored carbon is essential for new organ development in deciduous trees during early spring. However, the contribution of carbon to the development of new organs in early spring of subsequent years is not well understood. Using a ¹³C labelling approach, we investigated the reallocation of assimilated carbon into new aboveground organs on apple (Malus domestica) saplings in the following two years. Eight three-year-old potted saplings were exposed to ¹³CO₂ in an exposure chamber on each of eight different dates during the growth season. Some of the trees were harvested in the late autumn of the same year. The remaining trees were transferred to a field and cultivated during the two following growing seasons. We directly showed that the assimilated ¹³C was used to develop terminal and flower buds for two consecutive years after labelling. The proportions of the concentration of ¹³C remobilized to the terminal and flower buds in the second year were 5 and 24% of those in the first year after labelling, respectively. The concentration of assimilated ¹³C was higher in the terminal buds than in the flower buds in the first year after the labelling, while opposite results were found in the second year. This study demonstrates that the stored carbon used for the development of new organs was a mixture of recent- and old-stored carbon and indicates that recently-stored carbon was preferentially used to develop new organs. We also indicated that the stored carbon was remobilized to flower buds during development.

Pinellia ternata is an herb species in the Pinellia genus with significant economic value due to its medicinal properties. Understanding the accumulation and spatial distribution characteristics of metabolites during the development of the medicinal part, the rhizome of P. ternata (PR), provides a basis for targeted metabolic regulation and quality evaluation. In this study, we used matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI) and MS/MS to analyse metabolites at 5 representative stages (S1 to S5) of rhizome development in cross and longitudinal sections of the rhizome. A total of 168 metabolites were detected, with 13 being metabolites previously reported in PR. Additionally, Venn analysis revealed 12 bioactive differential metabolites during the growth process. Their spatial distribution and composition were analyzed, showing that alkaloids and amino acids were significantly distributed throughout the entire region and had higher relative contents compared to other metabolites. Flavonoids were more distributed in the outer regions of PR, potentially playing a greater role in combating biotic or abiotic stresses. Specifically, in cross-sections, arginine, nicotinamide, and 2-pentylpyridine showed a clear trend of accumulation from the outer to the inner from S1 to S5, while trigonelline, adenosine, cytidine, 3,4-dihydroxycinnamyl alcohol, raffinose, choline alfoscerate, liquiritin, and apii exhibited the opposite trend. For longitudinal sections, trigonelline, 2-pentylpyridine, choline alfoscerate and baicalein showed a trend of accumulation from the area of bud end to the far region during S1 to S5, while arginine showed opposite distribution trends. These findings deepen our understanding of the metabolic processes involved in the development of PR and have potential implications for variety improvement and quality control.

The gene GAD1 encodes a glutamate decarboxylase, which is a rate-limiting enzyme for the biosynthesis of endogenous γ-aminobutyrate acid (GABA), but a potential role of GAD1 in regulating cadmium (Cd) tolerance needs to be further elucidated in plants. The objective of this study was to investigate Cd tolerance of creeping bentgrass (Agrostis stolonifera) and transgenic yeast (Saccharomyces cerevisiae) or Arabidopsis thaliana overexpressing AsGAD1. The Cd-tolerant creeping bentgrass cultivar LOFTSL-93 accumulated more endogenous GABA in relation to a significant upregulation of AsGAD1 in leaf and root than the Cd-sensitive W66569 in response to Cd stress. The overexpression of AsGAD1 significantly enhanced Cd tolerance of yeast or A. thaliana associated with improved endogenous GABA content, low oxidative damage, and high cell membrane stability and photochemical efficiency. Compared with wild type, AsGAD1-overexpressing plants or the atgad1 mutant maintained significantly lower or higher Cd content in leaf and root by down-regulating or up-regulating transcript levels of AtNRAMP1/2/3/4/5 and AtZIP1/2, respectively. Moreover, overexpression of AsGAD1 significantly up-regulated transcript levels of AtHMA1/3, contributing to better Cd compartmentalization from chloroplast into cytoplasm and then into vacuoles. AsGAD1 overexpression also induced expressions of AsMT1A/1B/1C/2/3, AsGSH1/2, and AsPCS1/2, indicating better capacity of Cd chelation in cytosol and vacuoles for Cd detoxification. Hence, AsGAD1-regulated detoxification mechanism of Cd could be related to Cd uptake, transport, and chelation. In addition, lipid contents (PC, PG, and DGDG) and the DGDG/MGDG and PC/PG ratios were improved by the AsGAD1 overexpression, which favors membrane stability and functionality under Cd stress. These findings provide new insight into the regulatory role of GAD1 in Cd tolerance in plants.

In the context of climate changing environments, microalgae can be excellent organisms to understand molecular mechanisms that activate survival strategies under stress. Chlamydomonas reinhardtii signalling mutants are extremely useful to decipher which strategies photosynthetic organisms use to cope with changeable environments. The mutant vip1-1 has an altered profile of pyroinositol polyphosphates (PP-InsPs), which are signalling molecules present in all eukaryotes and have been connected to P signalling in other organisms including plants, but their implications in other nutrient signalling are still under evaluation. In this study, we conducted prolonged starvation in WT and vip1-1 Chlamydomonas cells. After N and P had been consumed, they showed important differences in the levels of chlorophyll, photosystem II (PSII) activity and ultrastructural morphology, including differences in the cell size and cell division. Metabolomic analysis under these conditions revealed an overall decrease in different organic compounds such as amino acids, including arginine and its precursors and tryptophan, which is considered a signalling molecule itself in plants. In addition, we observed significant differences in RNA levels of genes related to N assimilation that are under the control of the NIT2 transcription factor. These data are of important relevance in understanding the signalling role of PP-InsPs in nutrient sensing, especially regarding N, which has not directly been connected to these molecules in green organisms before. Additionally, the PP-InsPs regulation over cell size and photosynthesis supports novel strategies for the generation of resilient strains, expanding the biotechnological applications of green microalgae.

Shading is widely used in tea cultivation to improve quality by modulating various metabolic pathways in tea plants. However, the differential sensitivity of specific metabolites and the cultivar-dependent responses to shading are not yet fully understood. This study examined the impact of shading on the chemical composition and transcriptional profiles of cv. Longjing 43 and cv. Yabukita. Among the main quality-related compounds, flavonol glycosides were highly responsive to shading, while catechins displayed distinct cultivar-specific responses. KEGG enrichment analysis revealed that flavonoid biosynthesis was the key secondary metabolic difference between cv. Longjing and cv. Yabukita plants under the sunlight, and shading regulated flavonoid biosynthetic pathways in both cultivars. The genes such as ANTHOCYANIDIN REDUCTASE (CsANR) and ANTHOCYANIDIN SYNTHASE (CsANS) were less sensitive to shade in cv. Longjing 43 than cv. Yabukita, leading to relatively higher levels of epi-type catechins in the shade-treated cv. Longjing 43 sample. Additionally, the UVR8-mediated light signaling pathway demonstrated cultivar-specific expression patterns, although the functional roles of key signaling proteins were conserved across both cultivars. The insights into the chemical and molecular responses of tea plants to shading deepen our understanding of the mechanisms driving the cultivar-dependent behaviors of flavonoids, which offers valuable applications for maintaining consistent matcha quality and informing breeding programs of matcha.

An elicitor, chitosan (CHT), induces stomatal closure in plants, which is accompanied by salicylhydroxamic acid (SHAM)-sensitive peroxidases-mediated reactive oxygen species (ROS) production in guard cells. Reactive carbonyl species (RCS) function downstream of ROS in abscisic acid (ABA) and methyl jasmonate (MeJA) signalling in guard cells. However, the involvement of RCS in CHT-induced stomatal closure is still unknown. In this study, we used transgenic tobacco (Nicotiana tabacum) plants overexpressing Arabidopsis thaliana 2-alkenal reductase (AER-OE tobacco) and Arabidopsis wild-type (WT) plants to investigate whether RCS is involved in CHT-induced stomatal closure. Chitosan-induced stomatal closure was inhibited in the tobacco AER-OE plants. In the WT tobacco and Arabidopsis plants, CHT-induced stomatal closure was inhibited by RCS scavengers, carnosine and pyridoxamine. Chitosan significantly increased RCS production in the WT tobacco and Arabidopsis, but in the tobacco AER-OE plants, chitosan did not increase significantly RCS accumulation. Moreover, neither the application of RCS scavengers to both WT plants nor scavenging RCS by AER-OE affected the CHT-induced ROS accumulation. However, treatment with a peroxidase inhibitor, SHAM, significantly inhibited CHT-induced RCS accumulation in WT tobacco and Arabidopsis plants. Taken together, these results suggest that RCS acts downstream of ROS production in CHT signalling in guard cells of A. thaliana and N. tabacum.

The severe scarcity of wild resources of Ardisia crenata Sims (AS) has greatly limited its current clinical and pharmaceutical applications. We aimed to demonstrate the substitutability of stems and leaves for AS roots. In this study, 28 local samples from the Guizhou Province of China were selected for a comprehensive comparison of quality markers, chemical composition and efficacy. HPLC analysis showed that both stems and leaves contained bergenin, the main active ingredient of AS. Metabolomics studies showed that the chemical composition of the three parts was 99% similar. Network pharmacology analysis showed that similar signalling targets including STAT3 and MAPK1, AKT1 and EP300, SRC and TP53, were targeted by three parts. Animal experiments further demonstrated that extracts from the three different parts of the plant relieved the pathological symptoms of acute pharyngitis, and decreased serum inflammatory factors, showing similar efficacy. In sum, these findings strongly proved that stems and leaves can be used as supplements or substitutes for roots, providing a powerful strategy to solve the problem of AS resource shortage and greatly promoting the optimal utilization of AS. The study also anticipated some additional benefits, including the expansion of natural sources of bergenin and the discovery of potential cancer-related targets of AS.