Target-Based Physiological Modulations and Chloroplast Proteome Reveals a Drought Resilient Rootstock in Okra (Abelmoschus esculentus) Genotypes

Circadian-based approach for improving physiological, phytochemical and chloroplast proteome in Spinacia oleracea under salinity stress and light emitting diodes

Salt stress is a recognized annihilating abiotic stress that has a significant impact on agricultural and horticulture crop productivity. Plant development faces three distinct dangers as a result of salt stress: oxidative stress, osmotic stress, and ionic toxicity. It has been shown that plants can forecast diurnal patterns using the circadian clock; moreover, they can manage their defensive mechanism for the detoxification of reactive oxygen species (ROS). Circadian rhythmicity in gene expression assembles transcription and translation feedback networks to govern plant shape, physiology, cellular and molecular activities. Both external and internal variables influence the systemic rhythm via input routes. The Malav Jyoti (MJ) and Delhi Green (DG) genotypes of spinach (Spinacia oleracea) were grown in the plant growth chamber. The chamber had an optimized temperature of 25 °C and humidity of 65% containing light emitting diode (LED) having Red: Blue: white (one side) and White fluorescent (other side) under salinity stress. The samples were collected on the basis of 4 h intervals of circadian hours (0 h, 4 h, 8 h and 12 h) during Day-10 and Day-20 of salt treatments. Under salt stress, the circadian and light-emitting diode-based strategy had a substantial influence on spinach's anti-oxidative responses, stomatal movement, CO2 assimilation, PS-I and II efficiency, phytochrome pigment efficiency, and photosynthesis. Based on the findings of the free radical scavenging enzyme tests, the photoperiodic hours for the proteome analysis were set to 11 am and 3 pm on Day-20. When compared to white fluorescent, this study found that LED has the capacity to influence the entrainment cues of the circadian clock in the cultivation of salt-sensitive spinach genotypes. According to our findings, changing the cellular scavenging mechanism and chloroplast proteome has increased the survival rate of spinach genotypes under LED when compared to white fluorescent.

Grafting enhances drought tolerance by regulating and mobilizing proteome, transcriptome and molecular physiology in okra genotypes

Drought stress poses a serious concern to the growth, development, and quality of the okra crop due to factors including decreased yield, inadequate development of dietary fibre, increased mite infestation, and decreased seed viability. Grafting is one of the strategies that have been developed to increase the drought stress tolerance of crops. We conducted proteomics, transcriptomics and integrated it with molecular physiology to assess the response of sensitive okra genotypes; NS7772 (G1), Green gold (G2) and OH3312 (G3) (scion) grafted to NS7774 (rootstock). In our studies we observed that sensitive okra genotypes grafted to tolerant genotypes mitigated the deleterious effects of drought stress through an increase in physiochemical parameters, and lowered reactive oxygen species. A comparative proteomic analysis showed a stress responsive proteins related to Photosynthesis, energy and metabolism, defence response, protein and nucleic acid biosynthesis. A proteomic investigation demonstrated that scions grafted onto okra rootstocks increased more photosynthesis-related proteins during drought stress, indicating an increase in photosynthetic activity when plants were subjected to drought stress. Furthermore, transcriptome of RD2, PP2C, HAT22, WRKY and DREB increased significantly, specifically for grafted NS7772 genotype. Furthermore, our study also indicated that grafting improved the yield components such as number of pods and seeds per plant, maximum fruit diameter, and maximum plant height in all genotypes which directly contributed towards their high resistance towards drought stress.