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This study was conducted to investigate water conservation strategies in the above ground parts of Desmostachya bipinnata L., a perennial grass growing in populations of arid areas of the Punjab to identify variability in the anatomical traits that enable them to survive in water deficit conditions. Key structural modifications contributing to the ecological success and adaptation against heterogeneous environments included water conservation via development of additional water storage parenchyma, efficient conduction of solutes through wide metaxylem vessel (7947 µm2), minimization of water loss by intensive sclerification in some populations from Kallar Kahar (hyper-saline lake) and Pakka Anna (highly saline wasteland with Dratio:13.29) to avoid water loss. Populations from the most dry habitats, that is, in Cholistan (inter-dune desert flat with Dratio:43.17) had numerous small metaxylem vessels (1727 µm2). Saluwali (Cholistan Desert plain Dratio:30.4) populations showed intensive sclerification in stem vascular region and high density, wider metaxylem vessel oriented in dimensions different than other populations. A very unique feature observed in stems of Cholistan desert margin Kachakho, Pirowal plantation and Saluwali populations was the development of single-large metaxylem vessels instead of a pair usually found in plants. Another characteristic feature observed in stems, leaves and leaf sheath of some populations was differentially developed aerenchyma and bulliform cells ranging from small to large prominent and deeply inserted. In conclusion, D. bipinnata populations showed high but habitat-specific variability among the traits recorded, which provided this species a great potential to colonize arid and salt-affected areas. [ABSTRACT FROM AUTHOR]

The role of morpho-physiological attributes along with the antioxidant potential of Stipagrostis plumosa L. populations collected from arid regions in adaptability to aridity was evaluated. Root to shoot length, chlorophyll, carotenoids, and organic osmolytes (total free amino acids, total soluble proteins, glycinebetaine, and proline) increased with more activities of antioxidant enzymes (APX, CAT, POD, and SOD). Root and shoot fresh:dry weight ratio and leaf area decreased with increasing dryness ratio (D: 8.40-30.49) and decreasing precipitation (519 mm to 143 mm). Hyperarid populations [Noorpur Thal - NpT (D: 10.90; P: 400 mm) and Cholistan - Cho (D:30.49; P: 143 mm)] relied on reduced leaf area and plant biomass, longer roots, more activities of antioxidant enzymes with higher accumulation of organic osmolytes, and better compartmentation of ions in root and shoot. Root and leaf epidermal thicknesses, epidermal cell area, the proportion of cortical parenchyma, metaxylem cell area, abaxial stomatal density and area reduced significantly while stem epidermis thickness, cortical cell area, and metaxylem cell area increased in relatively less arid populations [Neela Wahn-NeW (D: 8.40; P: 519 mm) and Kallar Kahar-KKr (D: 8.99; P: 485 mm)]. In conclusion, survival of S. plumosa under water deficit was directly linked to the plasticity in morpho-physiological and anatomical traits such as epidermal hairs, thick leaves, intense sclerification in roots epidermis, cortex and endodermis, and vascular bundle. These traits not only accounted for the movement of water and solutes but also help conserve water and provided mechanical strength for survival in hyperarid environments. [ABSTRACT FROM AUTHOR]

Exogenous application of antioxidants can be helpful for plants to resist salinity, which can be a potentially simple, economical, and culturally feasible approach, compared with introgression and genetic engineering. Foliar spraying of alpha-tocopherol (α-tocopherol) is an approach to improve plant growth under salinity stress. Alpha-tocopherol acts as an antioxidant preventing salinity-induced cellular oxidation. This study was designed to investigate the negative effects of salinity (0 and 120mM NaCl) on linseed (Linum usitatissimum L.) and their alleviation by foliar spraying of α-tocopherol (0, 100, and 200mg L−1). Seeds of varieties "Chandni and Roshni" were grown in sand-filled plastic pots, laid in a completely randomized design in a factorial arrangement, and each treatment was replicated three times. Salinity significantly affected linseed morphology and yield by reducing shoot and root dry weights, photosynthetic pigment (Chl. a , Chl. b , total Chl., and carotenoids) contents, mineral ion (Ca2+, K+) uptake, and 100-seed weight. Concomitantly, salinity increased Na+, proline, soluble protein, peroxidase, catalase, and superoxide dismutase activities in both varieties. Conversely, the growth and yield of linseed varieties were significantly restored by foliar spraying of α-tocopherol under saline conditions, improving shoot and root dry matter accumulation, photosynthetic pigment, mineral ion, proline, soluble protein contents, peroxidase, catalase, superoxide dismutase activities, and 100-seed weight. Moreover, foliar spray of α-tocopherol alleviated the effects of salinity stress by reducing the Na+ concentration and enhancing K+ and Ca2+ uptake. The Chandni variety performed better than the Roshni, for all growth and physiological parameters studied. Foliar spray of α-tocopherol (200mg L−1) alleviated salinity effects by improving the antioxidant potential of linseed varieties, which ultimately restored growth and yield. Therefore, the use of α-tocopherol may enhance the productivity of linseed and other crops under saline soils. [ABSTRACT FROM AUTHOR]