Drought induced molecular and physiological adaptations in Ziziphus mauritiana and Salvadora oleoides under climate change scenario

Abstract

Water scarcity is one of the most impactful emerging challenges around the globe, enhancing the competition between domestic and agricultural usage. This scenario is even worse in arid and semi-arid areas owing to the low availability of water resources. The current research trial aimed to check the adaptability potential and leaf functioning of Ziziphus mauritiana and Salvadora oleoides under water stress. A pot experiment was conducted in the Forest Nursery and Experimental Area, Institute of Forest Sciences, The Islamia University of Bahawalpur. The four levels of water scarcity i.e., 60% field capacity (FC), 50% FC, 40% FC and 30% FC along with control were evaluated following a complete randomized design (CRD). The outcomes exhibited that water stress has a profound impact on the growth of both tree species. Water stress has reduced the plant height (41% & 43%), stem diameter (6.47% & 4.17%), shoot fresh weight (10.6% & 10.2%) and root fresh weight (40.21% & 44.07%) w.r.t control in Z. mauritiana and S. oleoides respectively. A similar trend was observed in biochemical parameters where the stress has induced higher enzymatic activities such as SOD (1.8 & 1.18 mg^-1 protein), POD (5.81 & 2.79 mg^-1 protein), CAT (1.93 & 0.68 mg^-1 protein) and MDA levels (0.039 & 0.034 mol g^-1 FW) respectively. Moreover, the photosynthetic pigments such as chlorophyll a, chlorophyll b, total chlorophyll and carotenoids also exhibited antagonistic responses towards drought stress. The overall results showed that Z. mauritiana performed better as compared to S. oleoides under drought stress levels. The outcomes of the study provide meaningful insights regarding the plantation on marginal lands in arid to semi-arid regions.