Journal of Plant Growth Regulation最新文献

Cold temperatures harm tropical crops, but understanding how molecular signals help plants cope could aid in climate change adaptation. This study tested if sodium nitroprusside (SNP), a nitric oxide (NO) donor, could improve potato tolerance to cold. Potato seedlings, treated or non-treated (0.5 mM) with SNP, were exposed to cold stress (0 and ‒2 °C) for 6 h. The study was conducted in a completely randomized design, incorporating three factors in three replications. Results showed that cold stress reduced physiological and biochemical parameters in all seedlings, but less so in those treated with SNP. SNP treatment boosted physio-biochemical activity and increased levels of soluble sugars and enzymatic and non-enzymatic antioxidants. Seedlings treated with SNP and exposed to cold stress had lower levels of H₂O₂ and malondialdehyde, suggesting that NO may alleviate the harmful effects of cold. The analysis conducted using PCA demonstrated correlations between variables and treatment groups. Notably, the first two principal components (PC1 and PC2) accounted for 77.6% and 78.1% of total variance, respectively, under both 0 and − 2 °C temperatures. Under temperatures below 0 °C, the results of the factor analysis (FA) revealed that PC1 exhibited the highest distribution of data, containing the most prominent variation in Squared cosine values (SCV) values at 0.79. Among the variables, Electrolyte leakage (EL) had the best representation in PC1, with the corresponding maximum SCV values at 0.78 under − 2 °C. This result highlights the potential use of SNP in manipulating cold tolerance in potato plants.

Amorphophallus muelleri, a naturally occurring variant of the commercially valuable Amorphophallus species grown in Southeast Asia, stands out for its desirable traits: high konjac glucomannan (KGM) content, apomictic properties, and strong disease resistance. However, the mechanisms governing KGM maturation and biosynthesis within A. muelleri seeds remain poorly understood. Accordingly, wide-targeted metabolomics and RNA-seq were used in the present study to analyze differentially accumulated metabolites (DAMs) and differentially expressed genes (DEGs). Importantly, we sought to identify changes during A. muelleri seed maturation and KGM biosynthesis. Our findings indicated that DAMs associated with amino acids and secondary metabolites were elevated in mature seeds. Moreover, the expression of several genes was also upregulated, including those involved in flavonoid biosynthesis and plant hormone signal transduction pathways, specifically TPS5, TPS6, C4H (CYP73A12), and key genes encoding auxin and abscisic acid (ABA) synthesis (IAA10, ARF11, SAPK7). Our findings suggest that these genes play positive roles in regulating seed maturation. Additionally, seven genes encoding key enzymes involved in KGM biosynthesis were upregulated during the first two stages of seed maturation compared to the third stage of seed ripening. This indicates a potential correlation between KGM content and the expression of these genes at the post-transcript level. Finally, a strong correlation was identified between key DAMs and DEGs. Collectively, these results provide valuable insights for researchers seeking to understand the molecular mechanisms underlying A. muelleri seed maturation and KGM synthesis.

Jasmonic acids, their effects on plant resistance and metabolites, have been extensively researched. However, methyl dihydrojasmonate (MDJ), a cost-effective and safe substitute for jasmonic acids, lacks sufficient research. This study presents a comprehensive analysis the impact of MDJ on Paris polyphylla var. yunnanensis. The present study aimed to enhance the accumulation of steroidal saponins (polyphyllin I, II, III, D, V, VI, VII, H) in Paris polyphylla var. yunnanensis which is a medicinal plant that contains medicinal steroidal saponins. To achieve this, different concentrations of MDJ were applied to Paris polyphylla var. yunnanensis. The study examined the impact of MDJ on physiology and polyphyllins. The optimal treatment concentration was identified, and the effects of MDJ on physiological metabolism and the expression pattern of related genes were explored. The results indicated that MDJ treatment significantly increased the levels of photosynthetic pigments, antioxidant enzymes, osmoregulators peaked at M2. Moreover, MDJ enhanced the accumulation of polyphyllins in both the leaves and rhizomes peaked at M2, particularly the sum of four polyphyllins (polyphyllin I, II, VI, VII) stated in the Chinese Pharmacopoeia, which increased by 45.65% following treatment. Based on transcriptome analysis, we revealed the polyphyllins-related genes by WGCNA. Furthermore, the majority of genes related to steroidal saponins were up-regulated following MDJ treatment. In the future, we recommend treating Paris polyphylla var. yunnanensis with suitable MDJ concentrations in production to efficiently enhance the yield of steroidal saponins.

Bulbils, originating from axillary meristem, are known to have a significant impact on the propagation of Lilium lancifolium. Transcription factor ASYMMETRIC LEAVES 1 has been shown to be involved in the regulation of bulbil formation based on the transcriptome data of L. lancifolium. The present investigation involved the cloning of the LlAS1 gene from L. lancifolium by RT-PCR and further be characterized. The open reading frame of LlAS1 comprised 1035 bp, which encoded 344 amino acids. The LlAS1 protein contained two conserved SANT domains in series at the N-terminus. Phylogenetic analysis revealed that LlAS1 belongs to the monocot group and was closely related to the AS1 of Musa acuminata subsp. malaccensis. Expression analysis showed that LlAS1 was strongly expressed in bulbil, especially in primary bulbils. It was highly expressed during the process of bulbil primordium establishment and bulbil formation. Transient overexpression and virus-induced gene silencing (VIGS) of LlAS1 in leaf axils significantly promoted and inhibited bulbil formation of L. lancifolium, respectively. The findings of the study indicated that LlAS1 was positively correlated with bulbil formation of L. lancifolium, laying a foundation for further understanding the regulation of LlAS1 gene for bulbil formation and application in molecular genetic improvement of lilies.

Changes in climatic conditions increase the frequency of severity caused by abiotic stress. Understanding the physiological responses to abiotic stress is crucial for developing action plans to increase stress tolerance in plants, whether through classical breeding, genetic engineering, or other innovative approaches. Gene editing in plants is a quickly advancing field that involves the targeted modification of plant genomes to achieve specific traits or characteristics. One of the plants’ most extensively used gene-editing technologies is Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein 9 (CRISPR-Cas9). CRISPR-Cas9 allows making precise changes to the DNA of plants by introducing targeted mutations. Efforts to address these challenges involve the development of stress-tolerant plant varieties through breeding, genetic engineering, and gene editing. These approaches aim to increase the ability of plants to withstand and recover from abiotic stress, ultimately improving crop resilience, quality, and yield in challenging environments. Additionally, sustainable agricultural practices and precision farming techniques can be employed to optimize resource use and mitigate the impact of abiotic stresses on crop production.

Drought significantly reduces crop yield, highlighting the need for effective strategies to combat its effects. Phytohormones like methyl jasmonate (MJ) offer promise in enhancing plant stress tolerance by bolstering defense mechanisms. Purple basil (Ocimum basilicum L.), a valuable vegetable renowned for its bioactive compounds, faces substantial damage from water scarcity. Hence, our study focuses on evaluating the efficacy of MJ application in alleviating drought stress in purple basil. For this, purple basil plants were grown in a completely randomized design in a 3 × 2 (irrigation frequencies × MJ treatments) factorial scheme, with seven replications. The growth, gas exchanges, chlorophyll fluorescence, photosynthetic pigments, relative water content, electrolyte leakage, sugars, phenolic compounds, and anthocyanins were determined. MJ treatment alleviated the deleterious effects of drought stress on growth, relative water content, and gas exchanges but decreased the chlorophyll fluorescence parameters of the plants. Moreover, MJ increased the contents of chlorophyll a, b, carotenoids, sugars, phenolic compounds, and anthocyanins, while reduced electrolyte leakage. Our findings indicate that MJ triggered the production of osmolytes and secondary metabolites, boosting antioxidant defense and photoprotection, while also mitigating electrolyte leakage and sustaining water balance, photosynthesis, and plant growth. In summary, MJ effectively relieved drought stress in purple basil by enhancing its photosynthetic capacity, secondary metabolism, and overall quality attributes.

Boron (B) is the most common trace element deficiency of cotton (Gossypium hirsutum L.) plantation in China. Whereas the narrow range of the deficiency and toxicity restrict the application of B, proline (Pro) mitigates many kinds of stress damage in plants, including B deficiency. How the pro-regulation of pro-metabolites affects plant growth, photosynthesis and leaf structure under boron (B) deficiency condition remains poorly understood. Here, this study investigates the effects of exogenous proline on the growth of Pro metabolites in cotton (E Kang 10) under B deficiency at different growth stages. We applied three Pro concentrations (0, 1.5 and 3 mg/L) with two B concentrations (0.1, 0.5 mg/L), with a total of six treatments. The addition of exogenous Pro at 1.5 mg/L significantly promoted the accumulation of B in leaves and increased the dry and fresh weight of various parts of the plant under low B stress. Additionally, the content of MDA was reduced, while the content of soluble protein increased in cotton plants under B_0.1 treatment after the addition of Pro. Both 1.5 and 3 mg/L of Pro increased the ratio of chlorophyll a/b under B stress. In the late stage, the synthesis of Pro is mainly promoted by regulating the activities of Arg, P5CS, P5CR and ProDH. Under two B levels, the application of Pro significantly reduced the Pro content in roots at both growth stages, which was related to the decrease in Arg, Glu, GSA and P5CS activities. Additionally, exogenous applicable Pro has a better-alleviating effect on low B stress of cotton seedlings.

In this study, a comparative evaluation was conducted on two different cultivars of Ocimum sanctum to determine the diversity of bacterial and fungal endophytes in root and shoot tissues. This assessment utilized both culture-based and culture-independent high-throughput sequencing approaches. Phylum and subsequently genus level information of bacteria and fungi revealed contrasting differences in the shoot tissue. CIM-Ayu cultivar was dominated by Firmicutes with Bacillus as most abundant genera, while Proteobacteria dominated the CIM-Angana cultivar that had major abundance of Pseudomonas. Overall, the operational taxonomic units (OTUs) information indicated dominance of Pseudomonas, Bacillus, Stenotrophomonas, and Flavobacterium genera in both the shoot and root samples of O. sanctum. Likewise, in case of fungal endophytes CIM-Ayu shoot was specifically enriched with Ascomycota while CIM-Angana was dominated by Basidiomycota. Notably, Saitozyma, Xenomyrothecium, and Cladosporium were the abundant fungal genera in shoot samples of CIM-Ayu while Fusarium, Corynespora, and Kazachstania dominated the root tissues. In total, 45 endophytes were discerned from the above- and belowground tissues of both O. sanctum cultivars through the implementation of a culture-dependent method. Further investigation of these isolates through the application of 16S rRNA and ITS gene sequencing substantiated that Bacillus and Pseudomonas were the prevailing genera. Furthermore, when all the isolates were screened for their plant growth promotion activity, Lysinibacillus irui An29 significantly enhanced the biomass, oil yield, and eugenol content. Overall, the amalgamation of metagenomics and culture-dependent techniques has furnished significant insights concerning potential bacterial endophytes that can be effectively employed in the field to facilitate growth promotion and enhance secondary metabolites in planta in forthcoming investigations.

In the past, scientific communities obtained the dose–response only partially right. They correctly described responses at high heavy metal (HM) doses, but ignored and mischaracterized the crucial response at low HM doses. Lower dosages of non-essential heavy metals (HMs) in plants induced plant hormetic responses by triggering innocuous, beneficial, and growth-promoting morpho-physio-biochemical reactions. Instead of creating toxic symptoms in plants, these low amounts of non-essential HM or metalloid dosages improve or boost plants’ metabolism at morphological, physiological, and biochemical levels. This review critically examines distinct non-essential HMs or metalloids-mediated hormetic effects inducing plant morpho-physio-biochemical response characteristics (end points) at specified exposure duration in diverse plant species. Additionally, the review highlights the details of hormesis inside the plant system along with non-essential heavy metal or metalloids-induced morphological, physiological, and biochemical hormetic responses that were clearly risk free, safe, and non-hazardous to plants’ bodies. These responses further ensured the plant’s fitness and long-term survival by strengthening the plant’s immunity against subsequent future interactions with toxicants. The review study also looks over the potential working possible mechanisms behind non-essential HMs or metalloids-induced phyto-hormesis phenomena, such as activation of a variety of plant tolerance mechanisms like phytohormone defence pathways, antioxidant system, stress-related genes, and reactive oxygen species (ROS) homeostasis. All these all mechanisms and their cross talk might contribute to plant growth and developmental processes under modest HMs or metalloids stress.

Ammonia (NH₃), which is an intermediate of nitrogen metabolism, has been found to be a gasotransmitter in plants. It has a dual physiological effect in a concentration-dependent manner, namely as a signaling molecule at low concentrations and a cytotoxin at high concentrations. In plants, NH₃, as a gasotransmitter, can maintain homeostasis by multiple pathways, which are involving in biosynthesis, assimilation, and transport. Gasotransmitter NH₃ can regulate plant growth, development, and response to multiple environmental stresses by crosstalk with other signaling molecules. However, a few reviews have summarized NH₃ homeostasis and its signaling role in plant growth and stress response. Hence, in this review, based on the progress in NH₃, whose toxicity, metabolism, and membrane transport were summarized. Also, the signaling role of NH₃ in cell division, seed germination, and root system architecture was discussed. Furthermore, NH₃-induced stress resistance, including drought, heat, salt, iron deficiency, elevated CO₂, and pathogen infection tolerance, was summed up. This review is to further understanding the gasotransmitter role of NH₃, and lays the foundation for designing and developing climate-resilient crops for food safety and sustainable agriculture.