Climate change is an invisible, silent killer with calamitous effects on living organisms. As the sessile organism, plants experience a diverse array of abiotic stresses during ontogenesis. The relentless climatic changes amplify the intensity and duration of stresses, making plants dwindle to survive. Plants convert 1–2% of consumed oxygen into reactive oxygen species (ROS), in particular, singlet oxygen (¹O₂), superoxide radical (O₂^•–), hydrogen peroxide (H₂O₂), hydroxyl radical (^•OH), etc. as a byproduct of aerobic metabolism in different cell organelles such as chloroplast, mitochondria, etc. The regulatory network comprising enzymatic and non-enzymatic antioxidant systems tends to keep the magnitude of ROS within plant cells to a non-damaging level. However, under stress conditions, the production rate of ROS increases exponentially, exceeding the potential of antioxidant scavengers instigating oxidative burst, which affects biomolecules and disturbs cellular redox homeostasis. ROS are similar to a double-edged sword; and, when present below the threshold level, mediate redox signaling pathways that actuate plant growth, development, and acclimatization against stresses. The production of ROS in plant cells displays both detrimental and beneficial effects. However, exact pathways of ROS mediated stress alleviation are yet to be fully elucidated. Therefore, the review deposits information about the status of known sites of production, signaling mechanisms/pathways, effects, and management of ROS within plant cells under stress. In addition, the role played by advancement in modern techniques such as molecular priming, systems biology, phenomics, and crop modeling in preventing oxidative stress, as well as diverting ROS into signaling pathways has been canvassed.

Rising atmospheric carbon dioxide (CO₂) and temperature alter gene-expression arrays commensurate with physio-morphological changes, resulting in issues of adaptation, growth patterns, and productivity of terrestrial vegetation. An experiment was conducted to investigate the adaptive response of Populus deltoides clone G48 to the combined effect of elevated CO₂ and temperature inside open-top chambers. The elevated CO₂ and temperature acted as environmental cues to help express upregulated/downregulated genes involved in important metabolic pathways. As a result, P. deltoides exposed to the elevated CO₂ and temperature developed adaptation to undo the effect by enhancing gaseous exchange, transpiration, and carbon assimilation and partitioning as observed on 180 days after treatment. The elevated conditions significantly enhanced stomatal density and size on adaxial/abaxial leaf surfaces, chlorophyll b that augmented photosynthesis, stomatal conductance, transpiration, and internal CO₂, but decreased instantaneous and intrinsic water-use efficiency. These stimulated biomass accumulation in root, stem, and leaves. Hence, the elevated conditions of CO₂ and temperature operate at the gene-expression level that acts pleiotropically for reinforcement of photosynthetic apparatus, morphological amendment for accelerated gaseous exchange, and finally growth and biomass improvement, supporting adaptive plasticity of clonal planting stock of the species to future climatic change and global warming.

Inter simple sequence repeats (ISSR) constitute a powerful dominant DNA molecular marker system used for diversity analysis, which is indispensable for making estimates of genetic base and demarcation of populations for undertaking conservation and improvement program offorest tree species. Twenty nine populations of teak (Tectona grandis L.f.) were collected from central and peninsular India for analysis of genetic diversity and structure. Genomic DNA from ten randomly selected individuals of each population was extracted and amplified using five ISSR primers (UBC-801, 834, 880, 899 and 900). The primers showed 100% polymorphism. UBC-900 recorded the highest Nei's genetic diversity (0.32 to 0.40) and UBC-899 had the highest Shannon's Information Index (0.49 to 0.59). AMOVA revealed a very high intra-population genetic diversity (91%), in comparison to inter-population genetic diversity among states (6.17%) and within states (2.77%), were also indirectly confirmed by large standard deviations associated with genetic diversity estimates for individual population, as well as poor bootstrapping values for most of the cluster nodes. However, UPGMA dendrogram revealed several clusters, with populations from central India being present almost in each cluster, making groups with populations of adjoining states and distant states. Nevertheless, the cluster analysis distinguished the drier teak populations of central India from the moist teak populations of south India, which was also confirmed by Principle Coordinate Analysis. The findings advocates the need not only for enhancing selection intensity for large number of plus trees, but also for laying out more number of in situ conservation plots within natural populations of each cluster for germplasm conservation of teak aimed at improving the teak productivity and quality in future.Â

Association between 276 AFLP loci and wood density of 46 teak (Tectona grandis L. f.) genotypes was evaluated, confirming the genetic structure among the genotypes and significant (p < 0.01) linkage disequilibrium between 9.4% loci-pair. AFLP markers with Bayesian correction for inbreeding coefficient detected a low genetic structure vis-à -vis high genetic diversity (0.23) and high polymorphism (57.41 ± 9.62%). AMOVA allocated 26.34% variation among the populations and 73.65% variation among the genotypes with FST = 0.16. The wood density with 8.71% variation displayed significant normal distribution. The careful control of statistical estimates incorporating Q and K to avoid the false discovery resulted in four AFLP loci significantly associated with the wood density trait. This is the first report dealing with marker-trait association in teak against the scarcity of background genomic information in this species. The AFLP markers associated with the wood density trait may be developed into STSmarkers for marker-assisted selection and breeding for genetic improvement of the species.