Physiology and Molecular Biology of Plants最新文献

Vegetable soybean [Glycine max (L.) Merr.] is gaining popularity because of its high nutritive values and health benefits; however, its productivity is scarce. Recognizing the need to accelerate breeding progress, a modified approach of ‘speed breeding’ was used in 16 vegetable soybean genotypes to reduce the breeding periods. The genotypes were exposed to cycles of 10 h light (30 °C) and 14 h dark (25 °C) with CO₂ (550 ppm) and without CO₂ supplementation under the light intensity of 220 µmol m⁻² s⁻¹ at the canopy level and 70–80% relative humidity. To reduce the time further, physiologically matured pods were harvested once they changed their color from green to greenish yellow and dried in the oven for 7 days at 25 ± 2 °C with RH 10–20%. The genotypes showed variable responses towards days to flowering coupled with an increase in the number of pods, number of seeds and seed weight per plant, and 100 seed weight during a short breeding period under CO₂ supplement. A couple of genotypes behaved indifferently under normal and elevated CO₂ levels. The fresh oven-dried seeds displayed 73.33–100% germination, while that in the seeds stored at 4 °C for 10 months was 80–100%. Thus, the modified speed breeding technique could effectively reduce the breeding period without affecting the germination of the seeds. With this approach, we could save 6–34 days in a genotype dependent way which would at least give 4–4.5 generations of soybean per year instead of the usual 1–2 generations. Further, the reduction in maturity duration was more in longer duration genotypes than the shorter duration ones. This represents the country’s initial report of rapid breeding in vegetable soybean and offers ample opportunity for rapid generation advancement in this crop.

Water deficit stress reduces crop yield in field crops, including sunflowers, at any growth stage. In response, most plants activate hormonal and gene expression patterns to mitigate damage. In this study, we evaluated changes in the physiological and gene transcription levels of two sunflower (Helianthus annuus L.) inbred lines -one sensitive (B59 line) and one water stress-tolerant (B71)–in response to water stress, by using mannitol to simulate water deficit conditions, which provides moderate stress in both sunflower lines. The analyses of the accumulation of various phytohormones under this stress revealed that Jasmonic acid (JA) significantly increased in the shoots of both lines. Similarly, Salicylic acid (SA) increased in the shoots of both lines, although it also accumulated in B71 roots. In addition, Abscisic acid (ABA) and Indole-3-acetic acid (IAA) showed a considerable increase in the B59 shoots. Regarding the JA and SA pathways, the WRKY70 transcription levels were higher in the shoots of both lines and the roots of B71. The B59 line showed overtranscription of a gene related to the ABA pathway (XERICO) and genes associated with IAA (ARF9 and ARF16 genes). The B71 line, on the other hand, simultaneously triggered the JA, SA and ABA hormonal pathways in response to this stress condition. The ABA and JA hormonal pathways activated different TFs, such as RD20, RD22, RD26, ANAC19 and ANAC29, through MYC2. Both the JA and SA hormonal pathways activated the WRKY70 transcription factor. Altogether, each line triggered the hormonal and transcriptional pathways in response to water stress, although at varying intensities. The results suggest that the hormonal pathways of JA, SA, IAA and ABA, along with their primary associated genes, are activated in response to water deficit at the early growth stage in sunflower seedlings, which mitigates damage.

Progesterone (PROG) has been detected at various concentrations in the environment and has adverse effects on humans and wildlife. This work evaluated the impact of PROG in Solanum nigrum L. plants, its removal capacity, and how 2,4-epibrassinolide (24-EBL) affects this process. Three treatments were used: (1) control, (2) irrigation with 0.8 µM PROG, and (3) treatment with 0.8 µM PROG after a pre-treatment with a foliar application of 1 µM 2,4-EBL (PROG/24EBL). After 20 days of treatment, no PROG was detected in the nutrient solution or plant tissues, indicating that the PROG was removed and metabolized. Lipid peroxidation significantly decreased in response to PROG in shoots and roots, and this effect was even more significant for both organs of the PROG/24EBL plants. Additionally, both treatments in both organs showed a decrease in H₂O₂ levels, and both steroid hormones increased the plants’ antioxidant system at both the biochemical and gene expression levels. In conclusion, S. nigrum can swiftly remove PROG without affecting its growth, and the use of 24-EBL synergistically decreases oxidative damage by increasing the activity of the antioxidant system and enhancing plant PROG removal ability.

Cadmium is one of the most hazardous environmental pollutants for plants due to its mobility and high toxicity. One effective method that may be utilized to decrease heavy metal pollution in the soil is the use of nano-chelated iron. In the present study, lettuce plants were treated with four different concentrations of cadmium chloride, two different concentrations of nano-chelated iron, and six combinations of cadmium chloride+nano-chelated iron. Application of 0.5 and 1 g/L nano-chelated iron reduced the adverse effects of cadmium on photosynthetic pigments and growth parameters. Combined application of cadmium chloride and nano-chelated iron (90 μg CdCl₂/g perlite+0.5 g/L nano-chelated iron) led to an increase in soluble sugar content compared to the control lettuce plants. Lettuce had a high capacity to absorb cadmium from the contaminated medium. Interestingly, the levels of cadmium that accumulated in the roots (1.641 mg/g DW) were much higher than in the aerial parts of the plant (0.998 mg/g DW). The results showed that there was a decline in the mineral content of lettuce treated with cadmium, while the application of nano-chelated iron led to its increase. This study suggests that the application of nano-chelated iron is a cost-effective and practical method that can be used in the agricultural soil systems to enhance crop tolerance in cadmium-polluted soil.

Maize dwarf mosaic virus (MDMV) is one of the most serious viruses of sweet corn. Utilising the process of RNA interference, the exogenous introduction of small RNA molecules mimicking virus-derived small interfering RNA (siRNA) into the plant prior to infection triggers the antiviral RNA silencing effect, thereby promoting more effective antiviral protection. Hence, a treatment with MDMV-derived small RNA was applied to sweet corn plants one day before MDMV virus inoculation. ALEXA FLUOR®488 fluorophore-bound exogenous siRNA was successfully detected inside intact sweet corn cells using confocal fluorescence microscopy. Furthermore, it was demonstrated that the exogenous siRNA treatment led to a notable upregulation of the AGO1, AGO2b, AGO10b, AGO18a, DCL1, DCL3a, DCL4, RDR1, and MOP1 genes within 24 h of the treatment. Overall, exogenous siRNA treatment resulted in better virus control of infected sweet corn plants, as indicated by the lower viral RNA and coat protein levels compared to the infected group without pre-treatment.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01500-2.

Drought stress poses a significant threat to global agriculture, highlighting the urgent need to elucidate the molecular mechanisms underlying plant drought tolerance. The UDP-glycosyltransferase (UGT) gene family plays crucial roles in diverse biological processes in plants. In this study, we conducted a comprehensive analysis of the UGT gene family in wild barley EC_S1, focusing on gene characteristics, subcellular localization, phylogenetic relationships, and protein structure. A total of 175 UGT gene family members were identified, exhibiting diverse patterns in protein length, molecular weight, isoelectric point, hydrophilicity, and subcellular localization. Most genes are located at chromosome ends. Phylogenetic analysis grouped the UGT genes into seven clusters, with barley-specific group E. Expression analysis across barley tissues showed upregulation in roots and senescent leaves, implying diverse roles. Under drought stress, expression patterns varied, with drought-tolerant varieties showing fewer changes than sensitive ones. Clustering analysis revealed distinct expression patterns, suggesting regulatory functions in barley's drought response. As a case, the HvUGT1 was cloned. Overexpression of HvUGT1 in Arabidopsis enhanced drought tolerance, with increased water retention, reduced cell damage, and elevated flavonoid levels. Conversely, HvUGT1 silencing in wild barley decreased drought tolerance, accompanied by reduced antioxidant enzyme activity and flavonoid content. These results highlight HvUGT1’s importance in enhancing plant drought tolerance, possibly through flavonoid-mediated ROS clearance. The research provides gene resources and valuable insights for the development of drought-resistant crops through targeted genetic manipulation strategies.

The current experiment was designed to evaluate the ramifications of simulated acid rain (SAR) on two pea (Pisum sativum L.) cultivars, Kashi Samridhi (Samridhi) and Kashi Nandini (Nandini), to decipher the intraspecific variations in defence mechanism considering the current scenario of rapid anthropogenic activities leading to increase in rain acidity. The pea cultivars were subjected to SAR of pH 7 (Control), 5.6, 5.0, and 4.5 under field conditions. SAR increased active oxygen species and malondialdehyde content due to increased lipid peroxidation in both cultivars; however, the increment intensity was more remarkable in Samridhi at the later growth stage. Ascorbic acid, thiol, and flavonoids were significantly increased in cultivar Nandini, along with increased peroxidase and superoxide dismutase activities. Total phenolics, glutathione reductase, and ascorbate peroxidase activities were enhanced considerably in Samridhi than in Nandini under SAR treatments. Higher stomatal density and stomatal size in Samridhi prompted greater acidic particles influx which further damaged the chloroplast and mitochondria. The present study concludes that cultivar Nandini is more proficient in inducing defence responses by elevating non-enzymatic antioxidants than Samridhi. Non-enzymatic linked defence mechanisms are more metabolically expensive, leading to less biomass accumulation in Nandini. The study depicted that innate defence responses, particularly the role of non-enzymatic antioxidants, governed the sensitivity level of cultivars towards SAR stress. Further, findings also contribute to bridging the knowledge gap regarding the responses of tropical and subtropical crops to acid rain.

Callus formation induced by auxin accumulation is considered the first step of in vitro plant regeneration. In Arabidopsis, degradation of the Aux/IAA protein, IAA14, in response to auxin signaling, which activates the AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 along with a series of downstream transcription factors, also plays a critical role in this process. However, the specific mechanism by which auxin regulates callus formation remains unclear. By screening mutant library in the solitary root 1 (iaa14/slr) Arabidopsis background we obtained the callus formation related 2 (cfr2) mutant. The cfr2 mutant exhibited a stronger capacity for callus formation, as well as lateral root and adventitious root regeneration from leaf explants than wild type (WT) seedlings, but did not recover gravitropism capability. The auxin signal in cfr2 was significantly enhanced, and the expression of some downstream transcription factors was increased. Map-based cloning, whole genome resequencing, and phenotypic complementation experiments showed that the phenotypes observed in the cfr2 mutant were caused by a point mutation in the IAA14 promoter region. This mutation, which is predicted to disrupt the binding of LBD16, LBD19, and LBD30 to the IAA14 promoter, changed the expression pattern of IAA14 in cfr2. Taken together, our results identified a new mutation in the IAA14 promoter region, which affects the expression pattern of IAA14 and in turn its ability to control plant regeneration.

Agriculture ecosystems are seriously threatened by lead (Pb) contamination, which impacts plant growth and productivity. In this study, green synthesized manganese oxide nanoparticles (MnO NPs) using citrus peel were used for priming of wheat seeds. For the synthesis of MnO nanoparticles, peel extract of Citrus paradisi and 1 mM solution of manganese acetate were stirred and calcinated at 500 °C. Successful synthesis of MnO NPs was determined using advanced techniques. In Fourier-transform infrared spectroscopy (FTIR), the presence of amines, alkanes, aldehydes, and alcohol molecules, on the surface of MnO NPs, confirmed their stability. X-ray diffraction analysis described their average size (22 nm), while scanning electron microscopy showed tetragonal crystalline shape and nano-flowers structure of MnO NPs. Sharp peaks of energy dispersive x-ray analysis described the presence of oxygen (28.81%) and manganese (71.19%) on MnO NPs. Priming of wheat seeds with synthesized MnO NPs significantly improved the growth attributes of wheat seedlings including the size of leaf, root length, size of shoots, chlorophyll and carotenoid contents, relative water content, decreased relative electrolyte leakage, high proline accumulation and decreased concentration of malondialdehyde. Application of MnO NPs also helped plants to accumulate antioxidant enzymes in their leaves. These results proved that the priming of MnO NPs can greatly reduce lead-induced stress in wheat seedlings and these NPs can also be used for the priming of other crops.