Physiologia plantarum最新文献

Innovations in light technologies (i.e. Light Emitting Diodes; LED) and cover films with specific optical features (e.g. photo-selective, light-extracting) have revolutionized crop production in both protected environments and open fields. The possibility to modulate the light spectra, thereby enriching/depleting cultivated plants with targeted wavebands has attracted increasing interest from both basic and applicative research. Indeed, the light environment not only influences plant biomass production but is also a pivotal factor in shaping plant size, development and metabolism. In the last decade, the strict interdependence between specific wavebands and the accumulation of targeted secondary metabolites has been exploited to improve the quality of horticultural products. Innovation in LED lighting has also marked the improvement of streetlamp illumination, thereby posing new questions about the possible influence of light pollution on urban tree metabolism. In this case, it is urgent and challenging to propose new, less-impacting solutions by modulating streetlamp spectra in order to preserve the ecosystem services provided by urban trees. The present review critically summarizes the main recent findings related to the morpho-anatomical, physiological, and biochemical changes induced by light spectra management via different techniques in crops as well as in non-cultivated species. This review explores the following topics: (1) plant growth in monochromatic environments, (2) the use of greenhouse light supplementation, (3) the application of covering films with different properties, and (4) the drawbacks of streetlamp illumination on urban trees. Additionally, it proposes new perspectives offered by in planta photomodulation.

Methylglyoxal (MG) is a highly reactive metabolic intermediate that plays important roles in plant salt stress response. This review explores the sources of MG in plants, how salt stress promotes MG production, and the dual role of MG under salt stress conditions. Both the positive role of low concentrations of MG as a signalling molecule and the toxic effects of high concentrations of MG in plant response to salt stress are discussed. The MG detoxification pathways, especially the glyoxalase system, are described in detail. Special attention is given to the novel role of the DJ-1 protein in the glyoxalase system as glyoxalase III to remove MG, and as a deglycase to decrease glycation damage caused by MG on DNA, proteins, and other biomolecules. This review aims to provide readers with comprehensive perspectives on the functions of MG in plant salt stress response, the roles of the DJ-1 protein in MG detoxification and repair of glycation-damaged molecules, as well as the broader functional implications of MG in plant salt stress tolerance. New perspectives on maintaining plant genome stability, breeding for salt-tolerant crop varieties, and improving crop quality are discussed.

Viroids are small, non-coding RNA pathogens known for their ability to cause severe plant diseases. Despite their simple structure, viroids like Potato Spindle Tuber Viroid (PSTVd) can interfere with plant cellular processes, including transcriptional and post-transcriptional mechanisms, impacting plant growth and yield. In this study, we have investigated the role of the Target Of Rapamycin (TOR) signaling pathway in modulating viroid pathogenesis in tomato plants infected with PSTVd. Our findings reveal that PSTVd infection induces the accumulation of the selective autophagy receptor NBR1, potentially inhibiting autophagic flux. Pharmacological inhibition of TOR with AZD8055 mitigated PSTVd symptomatology by reducing viroid accumulation. Furthermore, TOR inhibition promoted the recovery of autophagic flux through NBR1. It primed the plant defense response, as evidenced by enhanced expression of the defense-related gene PR1b and S5H, a gene involved in the salicylic acid catabolism. These results suggest a novel role for TOR in regulating viroid-induced pathogenesis and highlight the potential of TOR inhibitors as tools for enhancing plant resistance against viroid infections.

Plants have developed various strategies to deal with abiotic stresses throughout their lifetimes. However, environmental stresses can have long-lasting effects, positively modifying plant physiological responses to subsequent stress episodes, a phenomenon known as preconditioning or stress memory. Intriguingly, this memory can even be transmitted to offspring, referred to as "inter- or transgenerational memory". Chenopodium quinoa is a pseudocereal that can withstand several abiotic stresses, including nitrogen (N) limitation. This research highlights the critical role of maternal N conditions in shaping the physiological and metabolic responses of their offspring. Mother quinoa plants (F0) were grown under High N (HN) or Low N (LN) conditions. LN_F0 plants exhibited lower panicle biomass, net photosynthesis, and yield compared to HN_F0 plants. Seeds from LN_F0 retained proteins, reduced amino acids' levels, and increased lipids (such as PI 34:2), especially phosphatidylcholines, and their unsaturation level, which was associated with faster germination compared to HN_F0 seeds. Offsprings seedlings (F1) grown under either HN or LN had similar proteins and amino acid proportions of their seeds. However, LN_F0LN_F1 seedlings displayed significantly higher biomass and number of root tips. These changes were significantly correlated with transpiration, net photosynthesis, and stomatal conductance, as well as with starch content, suggesting higher CO₂ fixation at the whole plant level in LN_F0LN_F1 plants. Our findings suggest that quinoa transmits maternal environmental stress information to its offspring, modulating their resilience. This work underscores the potential of utilizing maternal environmental conditions as a natural priming tool to enhance crop resilience against nutritional stress.

Northern corn leaf blight, caused by Exserohilum turcicum (E. turcicum), is one of the most destructive diseases in maize, leading to serious yield losses. However, the underlying molecular mechanisms of E. turcicum infection response in maize remain unclear. In this study, we performed comparative transcriptome analysis in resistant maize inbred line J9D207 (R) and susceptible maize inbred line PH4CV (S) after infecting with E. turcicum at 0 h, 24 h and 72 h, respectively. Compared with 0 h, 9656 (24 h) and 8748 (72 h) differentially expressed genes (DEGs) were identified in J9D207, and 7915 (24 h) and 7865 (72 h) DEGs were identified in PH4CV. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that alpha-linolenic acid metabolism, benzoxazinoid biosynthesis, flavonoid biosynthesis and phenylpropanoid biosynthesis might be involved in maize defense reactions. Some DEGs coded for transcription factors, such as MYB-related, ERF, NAC, bZIP, bHLH and WRKY families, which indicated that they may participate in resistance against E. turcicum. In addition, DEGs involved in SA, JA, ABA and ET signaling pathways were revealed. Moreover, 75 SOD activity-related genes and 421 POD activity-related genes were identified through weighted gene co-expression network analysis (WGCNA), respectively. These results provide a novel insight into the resistance mechanism of maize in response to E. turcicum inoculation.

This review summarizes the impact of nickel (Ni) in hydroponics on the growth, basic biochemical parameters and oxidative balance in angiosperms using data from 66 papers (and 181 treatments). Generally, changes in biomass, pigments (chlorophylls and carotenoids) and proteins were negative when comparing concentration (≤100 and >100 μM) and time (≤14 and >14 days). However, we could deduce a higher tolerance to Ni excess in dicots than in monocots. Growth and basic metabolites were often significantly positively correlated. In contrast to proteins, amino acids were positively affected by Ni, indicating proline accumulation and/or protein catabolism. The increase in hydrogen peroxide (H₂O₂) content was stimulated by time and Ni concentration, and it is higher in dicots and usually negatively correlated with basic metabolites. An increase in Ni concentration stimulates the increase of thiols, but a longer exposure has a neutral or negative effect. On the contrary, the amount of vitamin C (ascorbic acid) is positively influenced by the dose of Ni in roots and the duration of excess Ni in shoots, which points to dynamic changes of this antioxidant in individual organs. Soluble phenols were not as affected, but their importance appears especially in shoots during long-term exposure to Ni with a simultaneous increase in H₂O₂ content, confirming their antioxidative role. We emphasize that due to the significant quantitative variability in the published studies, we analyze the presented parameters as a percentage change.

Polar tip growth in plants occurs only in root hairs and pollen tubes. In particular, root hair growth is considered very important in the growth of plants, as it is critical for water and nutrient absorption. Polar tip growth is regulated by various factors, including plant hormones such as abscisic acid (ABA) and gibberellin (GA) and cell wall modifications. We aimed to elucidate the effects and mechanisms on tip growth of a novel gene containing the domain of unknown function (DUF) 3511. We found that Protein Involved in Tip Elongation (PITE) is involved in root hair development in rice (Oryza sativa L.). PITE protein was observed in the plasma membrane and cytoplasm of root hairs. Pite mutants generated by the CRISPR/Cas9 system showed a shorter root hair phenotype compared to the wild type. Through RNA sequencing and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis, we found that the expression of genes that affect cell wall rigidity and GA metabolism-related genes were differently regulated in pite mutants. PITE could interact with acyl transferase and haloacid dehalogenase-like hydrolase (HAD9) in the nucleus and cytoplasm. Our study suggests that PITEs containing the DUF3511 domain regulate root hair growth in rice by mediating the expression of genes that can regulate cell wall rigidity or cause changes in GA metabolism through interactors such as HAD9.

Leaf senescence is the final stage of plant growth and development, characterized by chlorophyll degradation, organelle disintegration, and nutrient redistribution and utilization. This stage involves a complex and precise regulatory network, and the underlying mechanisms are not fully understood. Oilseed rape (Brassica napus L.) is one of the most important oil crops in China and globally. Therefore, mining and studying the key factors modulating leaf senescence and abscission in oilseed rape is of great importance to improve its yielding and nutrient use efficiency. In this study, we report that BnaMYB78 positively regulates leaf senescence in oilseed rape. As a transcriptional activator located in the nucleus, BnaMYB78 can bind to the SMRE7 (A/G)CC(T/A)AA(C/T) cis-element in vitro and positively regulate the expression of BnaPBS3, BnaMC9, and BnaNYC1 in oilseed rape. Overexpression of BnaMYB78 leads to chlorophyll degradation and premature leaf senescence in both Arabidopsis thaliana and oilseed rape. During this process, the expression of several genes associated with salicylic acid (SA) synthesis, chlorophyll metabolism, and senescence-associated genes (SAGs) was upregulated, including BnaPPH, BnaSAG14, BnaMC9, BnaPBS3, BnaNYC1, and BnaICS1, which facilitate the progression of programmed cell death (PCD). Further analyses demonstrated that BnaMYB78 activates the promoter activities of BnaMC9, BnaPBS3, and BnaNYC1 in a dual-luciferase reporter assay. Electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) assays revealed that BnaMYB78 directly binds to the promoter regions of these downstream target genes. In summary, our data demonstrate that BnaMYB78 modulates cell death and leaf senescence.

Plants are continuously attacked by several biotic and abiotic factors. Among abiotic factors, heat, cold, drought, and salinity are common stresses. Plants produce several hormones as their main weapon in fightback against these stresses. Among these hormones, the role of auxin is well established in regulating plant growth and development at various scales. However, in recent literature, the important role of auxin in abiotic stress tolerance has emerged. Several auxin signalling and transport mutants exhibit heat, drought, and salinity-related phenotypes. Among them, auxin-mediated hypocotyl elongation and root growth in response to increased heat are of importance due to the continuous rise in global temperature. Auxin is also involved in regulating and recruiting specialized metabolites like aliphatic glucosinolate to defend themselves from drought stress. Aliphatic glucosinolate (A-GLS) regulates guard cell closure using auxin, which is independent of the major abiotic stress hormone abscisic acid. This regulatory mechanism serves as an additional layer of guard cell movement to protect plants from drought. Transferring the aliphatic glucosinolate pathway into non-brassica plants such as rice and soybean holds the promise to improve drought tolerance. In addition to these, post-translational modification of auxin signalling components and redistribution of auxin efflux transporters are also playing important roles in drought and salt tolerance and, hence, may be exploited to breed drought-tolerant crops. Also, reactive oxygen species, along with peptide hormone and auxin signalling, are important in root growth under stress. In conclusion, we summarize recent discoveries that suggest auxin is involved in various abiotic stresses.