Wheat is a globally important crop used as a main staple food in various countries of the world. The current study was conducted with the objective to evaluate the effect of a high temperature (HT) on osmolytes (starch, sucrose, total soluble sugars, total soluble proteins and proline), physiological parameters (Chl-a, Chl-b, photosynthesis rate, transpiration rate and stomatal conductance), antioxidant enzymes (superoxide dismutase, catalase and peroxidase) and agronomic traits (flag leaf area, spike length, and thousand grain weight) during the grain filling and anthesis stages of wheat cultivars (Fakhr-e-Bhakar, Raj-3765, Jimai-22 and Bayraktar-2000) collected from different regions of the world. Separate experiments for both stages were conducted in a glasshouse and treated with two different temperature regimes, i.e., optimum (OT) (24 °C day; 14 °C night) and high temperature (HT) (32 °C day; 22 °C night) in RCBD for two weeks. The data for osmolytes, antioxidant enzymes and physiological contents were collected at days 3, 5, 7, 9 and 13 after the start of plant stress, while the agronomic traits were collected at maturity. The data obtained were subjected to a statistical analysis using the statistix8.1 and R-program. HT stress significantly reduced all the traits except for the membrane damage, transpiration rate, proline and total soluble sugars, whose values increased considerably in the genotype Bayraktar-2000. However, under both regimes of temperature Fakhr-e-Bhakkar showed a high tolerance against HT stress, as revealed by physiological, biochemical and agronomic evaluations. Moreover, correlation, PCA and heat map analyses indicated that all types of traits are significantly interconnected in determining the crop potential to sustain its growth under HT stress.

The tolerance to salinity stress is an intricate phenomenon at cellular and whole plant level that requires the knowledge of contributing physiological and biochemical processes and the genetic control of participating traits. In this context, present study was conducted with objective to evaluate the physiological, biochemical, and genetic responses of different wheat genotypes including bread wheat (BW) and synthetic hexaploids (SHs) under saline and control environment. The experiment was conducted in two factorial arrangement in randomized complete block design (RCBD), with genotypes as one factor and treatments as another factor. A significant decline in physiological traits (chlorophyll, photosynthesis, stomatal conductance, transpiration, and cell membrane stability) was observed in all genotypes due to salt stress; however, this decline was higher in BW genotypes as compared to four SH genotypes. In addition, the biochemical traits including enzymes [superoxide dismutase, catalase, and peroxidase (POD)] activity, proline, and glycine betaine (GB) illustrated significant increase along with increase in the expression of corresponding genes (TaCAT1, TaSOD, TaPRX2A, TaP5CS, and TaBADH-A1) due to salt stress in SHs as compared to BW. Correspondingly, highly overexpressed genes, TaHKT1;4, TaNHX1, and TaAKT1 caused a significant decline in Na⁺/K⁺ in SH as compared to BW genotypes under salt stress. Moreover, correlation analysis, principal component analysis (PCA), and heatmap analysis have further confirmed that the association and expression of physiological and biochemical traits varied significantly with salinity stress and type of genotype. Overall, the physiological, biochemical, and genetic evaluation proved SHs as the most useful stock for transferring salinity tolerance to other superior BW cultivars via the right breeding program.

. The plant growth regulator 6-benzylaminopurine (BAP) is an important component of plant nutrient medium with tendency to accelerate physiological, biochemical and molecular processes in woody plants such as olive. To date, limited knowledge is available on the role of BAP in mediating physiological, biochemical and genetic activities in olives under in vitro conditions. To cover this research gap, the current study was conducted with the objective of studying the role of BAP in regulating physiological traits (chlorophyll, CO₂ assimilation), antioxidant enzymes (superoxide dismutase, catalase and peroxidase), metabolic contents (starch, sucrose and flavonoids) and gene expression (OeRbcl, OePOD10, OeSOD10, OeCAT7, OeSS4, OeSuSY7, OeF3GT and OeChlH) under varying concentrations (0, 0.5, 1.5 and 2.5 mg L⁻¹) within the provided in vitro conditions. The explants obtained from different olive cultivars (‘Leccino’, ‘Gemlik’, ‘Moraiolo’, ‘Arbosana’) were cultured on olive medium (OM) provided with different BAP concentrations using a two-factorial design, and data were analysed statistically. All traits increased significantly under in vitro conditions due to increasing concentrations of BAP; however, this increase was more dramatic at 2.5 mg L⁻¹ and the least dramatic at 0.5 mg L⁻¹. Moreover, correlation, principal component analysis and heatmap cluster analysis confirmed significant changes in the paired association and expression of traits with changing BAP concentration and type of olive cultivars. Likewise, the expression of all genes varied due to changes in BAP concentration in all cultivars, corresponding to variations in physiological and biochemical traits. Moreover, the spectrographs generated via scanning electron microscopy further indicated the variations in the distribution of elements in olive leaf samples due to varying BAP concentrations. Although all cultivars showed a significant response to in vitro varying concentrations of BAP, the response of Arbosana was statistically more significant. In conclusion, the current study proved the dynamic impact of the varying BAP concentrations on regulating the physiological, biochemical, and molecular attributes of olive cultivars.