Journal of Plant Growth Regulation最新文献

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.

Nano-fertilizers with higher efficacy compared to conventional fertilizers can provide advantage for plant cultivation in both productive and problematic soils. Therefore, this study aimed to determine the effect of nano-calcium (nano-Ca) on lettuce plants grown in saline-boron toxic soil. Nano-calcium fertilizer was prepared from eggshells. Functional and structural properties of nano-Ca was determined by scanning electron microscopy (SEM), x-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR) before plant experiment. The treatments was; control, 40 mM NaCl and 20 mg kg⁻¹ B (NaCl + B), and 40 mM NaCl and 20 mg kg⁻¹ B with 4 mM Nano-Ca (NaCl + B + nano-Ca). The nano-Ca significantly increased the dry weight and calcium (Ca) concentration of lettuce plants under saline-B toxic conditions. Although there was a decrease in the concentrations of sodium (Na), chloride (Cl), and boron (B) with nano-Ca treatment, it was not statistically significant. Salinity and boron toxicity lead to increased lipid peroxidation. In the present study, the production of malondialdehyde (MDA) as a marker for lipid peroxidation, along with a significant decrease in hydrogen peroxide (H₂O₂) concentration, was observed with the application of nano-Ca. There was no significant alteration in superoxide dismutase activity (SOD) observed in lettuce grown under saline and boron toxic conditions. However, catalase activity (CAT) increased with nano-Ca application, while the activity of ascorbate peroxidase (APX) decreased. The study results suggest that nano-Ca serves a protective function for lettuce plants cultivated under saline and boron toxic conditions.

Phytohormones are the key regulators of plant growth, development, and responses to environmental stressors. Among these, jasmonates (JAs) are particularly crucial, derived mainly from α-linolenic acid (α-LA). JAs govern various physiological processes like seed germination, root elongation, and apical hook formation, while also influencing secondary metabolite production and defense mechanisms. Interacting with enzymes, genes, and other growth regulators, JAs modulate intricate signaling pathways, activating metabolic responses in both normal and stressed conditions. Transcription factors such as MYB, WRKY, basic Helix-Loop-Helix (bHLH), and APETALA2/JA-responsive ethylene response factor (AP2/ERF) are central components to JA signaling pathways, impacting the synthesis of bioactive compounds of therapeutic potential. Additionally, JAs act as chemical elicitors, promoting secondary metabolite production in vitro, leveraging advancements in plant cell and tissue culture techniques. In this regard, the present review offers a comprehensive discussion on diverse roles of JAs in plant physiology and biochemistry, including its biosynthesis, and suggests strategies for large-scale bioactive compound production via plant cell and tissue culture methods.

Apple (Malus domestica) is an important economic fruit crop of the temperate regions of world. Apple productivity is known to be affected by several biotic and abiotic stresses. Among these, water scarcity and soil salinity significantly impact the physiological and metabolic processes of apple, leading to economic losses. Apple plants employ intricate physiological responses to combat drought and salt stress which are orchestrated by diverse endogenous molecular regulatory mechanisms. Modern ‘-omics’ analyses have unraveled the roles of various transcription factors in restoring cellular homeostasis and alleviating the adverse effects of drought and salinity stress on apple plants. Important functions of various miRNAs have recently been studied in the post-transcriptional regulation of gene expression under both stresses. Several protein-mediated regulatory networks underlying drought and salt stress adaptation responses in apple have lately been deciphered. All these regulons ultimately induce the biosynthesis and accumulation of protective compounds for mitigating the negative effects of drought and salinity stress on apple growth. This review coherently highlights a bunch of candidate genes involved in regulating drought and salinity stress in apple and is an exemplification of our present understanding of how apple plants respond to these stresses. The functions of these genes can further be carefully exploited for developing apple varieties with anticipated levels of drought and salt stress tolerance.