Journal of Plant Growth Regulation最新文献

Phytohormones are natural signaling molecules, developed and deployed by plants to tackle diverse biotic and abiotic stresses, thus holding great significance. Over the past few decades, growing evidence has suggested that jasmonates, a comparatively newer class of stress-responsive phytohormone, are involved in a multifaceted role of physio-biochemical processes consolidated so far in plants. Jasmonates are known to interact with five major phytohormones, often called “the big five” such as auxin, gibberellins, cytokinins, abscisic acid and ethylene, as well as plant growth regulators (PGRs) including brassinosteroids, strigolactones, salicylic acid, nitric oxide, melatonin, polyamines and hydrogen sulfide for resource allocation to maintain a dynamic balance between basal growth and plant defense response under suboptimal conditions. The detailed knowledge of coordinated relationships among multiple phytohormones along with PGRs and their interconnected networks by means of synergistic and antagonistic actions is crucial for understanding plant adaptations during environmentally challenged situations. In the present review, we provide a broad overview of jasmonate signaling pathways, starting from biosynthesis, metabolism and signal transduction pathways, together with the intricate crosstalk mechanism among jasmonates, major phytohormones and PGRs, based on recent advancements in research. The molecular basis of crosstalk and the key components of signaling pathways are also discussed in this review, which can be utilized for better stress management programs through the manipulation of phytohormone signaling under hostile environment.

Arsenic (As), in the form of arsenate [As(V)], enters into the plants through phosphate transporters and hence it was postulated that the utilization of rice varieties with high phosphorus use efficiency (PUE) might assist in reducing As accumulation. To explore the interaction between arsenic (As) and phosphorus (P) in rice plants, with a focus on reducing As accumulation in rice grains. The research utilized hydroponic cultivation of 15 rice genotypes under varying P levels (optimum: 0.32 mM, deficit: 0.16 mM, 0.08 mM, 0.032 mM) for screening. Two contrasting genotypes were chosen based on PUE and growth response: variety DNA Sribala (DS) demonstrated the highest PUE, while Sai Kasturi (SK) exhibited the lowest PUE. These selected genotypes were then analyzed for physiological response, antioxidant enzyme activity, and elemental accumulation (P, As) under various treatments such as control, As, ½ P, ½ P + As, ¼ P, and ¼ P + As, spanning durations of 7 and 12 days. Results indicated that under the ¼ P + As condition, SK exhibited significant physiological damage, including increased electrolytic leakage and malondialdehyde content. Arsenic accumulation was notably higher in SK than in DS across all treatments, while P accumulation displayed the opposite trend. Maximum observed As accumulation was 2022 µg g⁻¹ at 12 days in SK roots under the ¼ P + As condition, whereas DS showed lower As accumulation 1241 µg g⁻¹ under the same treatment. A differential expression pattern of phosphate transporters, Pht1;1 and Pht1;8 was also observed in root and shoot of DS and SK. The study concludes that rice varieties with high PUE, like DS, may be recommended for cultivation in As-contaminated areas to mitigate As contamination in rice grains.

Phytohormones are crucial regulators to boost-up plant growth and development under stressful situations. Plants have adapted many phytohormone signaling pathways to get around the challenging environmental restrictions and lessen the detrimental effects on crop growth progressions and productivity. Strigolactones (SLs), a new class of phytohormones, have played a role in a number of plant developmental processes. Due to their crucial functions in the control of numerous physiological and molecular activities during the response of plants to abiotic stressors, SLs have recently attracted a lot of interest. The SL enhances abiotic stress tolerance via different mechanisms including, regulation of photosynthetic attributes, antioxidant enzyme activities, ionic homeostasis, gene expressions, and reducing oxidative damage. Stomatal regulation is an inevitable process under stress to regulate gas exchange and transpirational loss. Literature shows that SL are often used regulators that induce stomatal closure in plants. However, the details mechanisms of SL-mediated stomatal movement have not been clarified adequately. In addition, since the initial discovery, significant progress and fresh information about the biosynthesis, signaling, and transport of SLs have been revealed. However, in this review, we provide a fundamental overview of SL perception and biosynthesis along with a thorough explanation of how we now understand SLs and their crucial function in tolerating environmental restrictions. The involvement of SLs in guard cell signaling and future research gap are highlighted.

Low crop Nitrogen Use Efficiency (NUE) is an economic and environmental burden. Rice is an attractive target for NUE improvement in India, due to its highest N-fertilizer consumption and the availability of a vast germplasm. We screened 12 Indica rice genotypes (Oryza sativa ssp. Indica) on modified Arnon-Hoagland (AH) media containing graded urea doses from 0 to 7.5 mM (U₀, U₁₀, U₅₀, or U₁₀₀). We identified six genotypes with contrasting crop duration and germination rate for their life-long evaluation of 46 morpho-physiological parameters, including NUE, using at least 30 potted plants per genotype/treatment grown on nutrient-free soil supplemented with AH media containing urea as the sole N-source (U₁₀, U₅₀, or U₁₀₀). We found significant genotype and N-dose-dependent effects of urea that correlated positively for 28 of the phenotypic parameters including five for NUE, whereas three parameters showed a negative correlation for urea dose. We also found a significant positive correlation with genotype and urea dose–response for eight physiological parameters, including one for NUE, while seven parameters showed a negative correlation, including two for NUE. A ranking of all 6 genotypes by N-responsive yield and NUE revealed that the late-germinating, long-duration genotypes had better yield and NUE than the early germinating, short-duration genotypes. The only exception was Dhala Heera from the latter group, which had the preferred combination of early (short) duration and high NUE across all urea doses. This makes it a promising donor genotype for further field evaluation and crop improvement toward higher NUE.

The longevity of cut flowers is associated with various physio-biochemical traits. To extend vase life (VL) of cut flowers, a wide range of chemical-based preservatives solutions have been used, which raise the concerns of human health and environmental pollution. This study explored the potential of using ascorbic acid (AsA) to naturally extend the VL of cut sword lily (Gladiolus grandifloras) ‘White Prosperity’ flowers. Fresh spikes were placed in vase solutions containing 1, 2, 3 and 4% AsA solutions, denoted as AsA1, AsA2, AsA3 and AsA4, respectively, as well as distilled water (DsW) as control. The AsA solutions prolonged the VL from 5.75 to 12.5 days. The treatment AsA4 significantly improved the relative fresh weight, floret diameter, the number of open florets, and chlorophyll contents. Ascorbic acid decreased oxidative stress (malondialdehyde and hydrogen peroxide) and boosted proline and total soluble proteins levels in cut sword lily, indicating a link with reduced water stress. AsA application improved phenols and sugars in the florets. Bacterial count was low in AsA-based vase solutions. Overall, AsA4 had the best performance with respect to VL and other associated traits. Given the encouraging outcomes of the ongoing research, AsA may be recommended as a viable postharvest treatment to extend the VL of sword lily.

Salinity significantly impairs plant growth and development, and effective strategies are required to mitigate its detrimental effects. Previous studies did not document myo-inositol (MYO) influence on vital processes such as photosynthesis, methylglyoxal production, redox balance, and ion homeostasis in plants subjected to saline conditions. The literature lacks comprehensive insights into the myo-inositol-mediated modulation of pivotal tolerance mechanisms. Hence, our study fills this significant gap by elucidating the intricate role of MYO in augmenting plant resilience to salinity stress, shedding light on its multifaceted impact on key physiological pathways essential for plant adaptation and survival. This study investigated the potential of MYO as a mitigating agent against NaCl and KCl salinity in maize plants. Two maize cultivars with differential salinity tolerance (salt-tolerant cv. Pearl and salt-sensitive cv. Malka-2016) were subjected to 12 dS m^‒1 salinity of NaCl and KCl. The findings revealed that MYO (25, 50, and 75 mg L^‒1) enhanced plant growth under salinity by improving chlorophyll content, photosynthesis, antioxidant compounds, antioxidant enzyme activities, and nutrient acquisition. Myo-inositol promoted leaf relative water content by improving osmotic adjustment due to the accumulation of osmolytes such as proline, soluble sugars, and free amino acids. MYO significantly increased nitrate reductase activity alongside higher H₂S and nitric oxide levels. These observations suggest that MYO influences plants' antioxidant capacity and metabolic responses to salinity. Notably, MYO effectively diminished reactive oxygen species generation and lipid peroxidation, thereby improving plant growth under salinity. Conclusively, MYO significantly improved growth, decreased oxidative injury and promoted photosynthesis, osmotic adjustment, and antioxidant defense system under salinity. These findings indicate that MYO is a potential growth regulator and stress mitigator, offering promising prospects for sustainable crop production in saline environments.

Illuminate the genome-wide dynamic response to salt stress in Periploca sepium Bunge and the mining of the key salt-tolerant genes. After 30 days of growth and treatment with 1% NaCl, transcriptome sequencing was performed and select genes were tested for RT-qPCR to ensure transcriptome accuracy. The results showed that there were 2225, 2579, 3852 and 3811 differentially expressed genes (DEGs) under salt stress for 4 h, 12 h, 24 h and 48 h, respectively. In the early stage, the redox balance in P. sepium was broken, and with the increase of ROS, the expression of antioxidant enzymes was also increased, and plant growth was inhibited, which was manifested in the significantly down-regulated expression of GA synthesis genes. With the increase of salt stress time, the process of energy metabolism and resource recombination in P. sepium was strengthened, and protein degradation and synthesis occurred accordingly. After 2 days of response adjustment, the differential genes in plants gradually stabilized, and the expression of genes related to reducing substances such as flavonoids was significantly up-regulated, and the plants re-established a stable state to adapt to the new environment.

Anthropogenic activities increased heavy metals in agricultural systems, increasing nickel (Ni) and vanadium (V) concentrations. Wheat, being an assurance of food security worldwide, can be severely affected by the presence of Ni and V in the soil system. Wheat cultivars possess varied responses to Ni and V. Hence, it seems logical to explore the innate potential of different cultivars to fight against these heavy metals. In the present study, five wheat cultivars were exposed to different Ni and V concentrations. To evaluate the innate tolerance of wheat cultivars to Ni and V toxicity, germination profile, starch metabolism, antioxidant enzyme activities, metabolites, membrane stability index, and ions uptake by wheat seedlings were recorded. Results depicted that wheat cultivars showed differential responses to Ni and V toxicity. The cultivar AARI-2011 performed better than other cultivars in terms of studied parameters. Hence, it can be concluded that the above-mentioned parameters can be employed to explore wheat cultivars’ tolerance to Ni and V.

In recent years, nanocarriers have been employed for the encapsulation and sustained release of agrochemicals with a particular focus on auxins. Given their potential applications, they have attracted significant interest in order to enhance bioavailability and improve crop yields and nutrient quality. The synthesis and efficacy of hollow mesoporous silica nanoparticles (HMSNP_S) as a nanocarrier for the loading of the hormone indole-3-butyric acid (IBA) and its effect on rooting tobacco plants have been investigated in this study. The physicochemical properties of the nanoparticles were confirmed through a comprehensive range of analyses. The average particle size of the IBA-HMSNP_S was measured by Dynamic light scattering analysis of 452 nm (nm). Scanning electron microscope studies revealed that the nanoparticles were spherical in shape with an average size of approximately 85 nm. The characteristic peaks of IBA on HMSNP_S were identified by Fourier transform infrared spectroscopic analysis. Furthermore, a hormone loading efficiency (HLE) of 45% was observed, and an encapsulation efficiency (EE) of up to 90% was observed for IBA hormone loading. The results revealed that for the traits assessed, the average root length and the longest root length were 9.43 and 10.30 cm, respectively, observed in the IBA-HMSNPS treatment with a concentration of 1 mg L⁻¹. The treatment of IBA-HMSNPS at a concentration of 3 mg L⁻¹ demonstrated the highest values for root fresh weight (1.03 g), dry weight (0.07 g), and days to rooting (2.66 days), respectively. The study’s findings suggest that hollow mesoporous silica nanoparticles (HMSNP_S) serve as a promising nanocarrier for delivering indole-3-butyric acid (IBA) hormones in agricultural contexts.

Tetrastigma hemsleyanum is a perennial evergreen vine of the Vitaceae. The entire herb is used in traditional Chinese medicine as a broad-spectrum plant-based antibiotic, so it has high economic and social value. Wild T. hemsleyanum resources are scarce, so it has been declared an endangered and rare medicinal plant. Seed yield is low and vegetative propagation by cuttings results in limited plant production, so development of the T. hemsleyanum industry requires optimized propagation protocols and the development of new biotechnologies to proliferate this plant in commercial quantities. In this study, shoot organogenesis was successfully induced from leaves and petioles. Two plant growth regulators, 6-benzyladenine (BA) and thidiazuron, induced callus and adventitious shoots, but the ideal adventitious shoot induction medium was Murashige and Skoog (MS) medium containing 1.0 mg L⁻¹ BA and 0.1 mg L⁻¹ α-naphthaleneacetic acid (NAA). This resulted in a shoot proliferation coefficient (SPC) of 6.73 within 30 d at a light intensity of 100 µmol m⁻² s⁻¹. When light intensity was increased from 50 to 200 µmol m⁻² s⁻¹, SPC (7.35), chlorophyll a (Chl a), Chl b, and total Chl (a + b) content increased. On MS medium containing 0.1–2.0 mg L⁻¹ NAA or indole-3-butyric acid, 100% of adventitious shoots formed adventitious roots. Plantlets showed no obvious morphological variation, and their survival exceeded 98% on a substrate of peat and river sand (v:v = 2:1). This study’s protocols allow for the mass production of adventitious shoots for conservation purposes, and potentially for the commercial propagation of T. hemsleyanum.