Morphological, physiochemical and antioxidant responses of Maclura pomifera to drought stress

Abstract

Drought is one of the most important environmental factor limiting the growth of woody and non woody plants. In the present paper, we aimed to explore the performance of Maclura pomifera under a prolonged drought period followed by re-watering. M. pomifera plants were exposed to four different watering regimes (100%, 75%, 50% and 30% of the field capacity (FC)) for three weeks and then rewatered. The exposure to drought affected physiological, morphological and biochemical traits of M. pomifera. Leaf area, relative water content and water potential of leaf decreased in parallel with increased water deficit. Malondialdehyde content increased along with the drought stress experiment. Soluble carbohydrates (sucrose, glucose and fructose) accumulated during drought stress, but decreased after 22 days of water deficit in severe stressed plants (30% FC). Proline and mannitol, two compatible osmolytes, were higher in drought stresses plants than in control plants. Additionally the activity of antioxidant enzymes (SOD, APX, DHAR and GR) resulted affected by drought stress. In the recovery period, the physiological parameters as well as the proline content recovered at control levels, whereas soluble sugars, mannitol and total activity of antioxidant enzymes remained slight higher than in control plants, presumably to allow plants a complete recovery after stress. Our results suggest that M. pomifera has a good adaptive response to drought stress, probably corresponded to decreasing oxidative injury by induction of the antioxidant system and accumulation of stable and protective osmolytes such as proline and mannitol at higher rates.

Reactive oxygen species scavenging mechanisms associated with polyethylene glycol mediated osmotic stress tolerance in Chinese potato

“…Our previous studies in taro, a carbohydrate-rich tuber crop, demonstrated the detrimental effect of PEG on shoot proliferation in vitro 29 . Reports have also shown that limited www.nature.com/scientificreports www.nature.com/scientificreports/ water availability restricted cell division and elongation and thereby hinders plant growth and development 30,31 . The extent of plant growth inhibition depends on the genotype and the severity of stress; which was prominent in our study across the studied genotypes.…”

“…ROS generated inside the cell as a result of oxidative stress can target the lipid membranes resulting in elicitation of the lipid peroxidation 31,32 . Increased MDA content is considered as a hallmark of membrane lipid peroxidation and also an indicator of free radical prevalence in the tissues.…”

Drought-hardening improves drought tolerance in Nicotiana tabacum at physiological, biochemical, and molecular levels

“…It is well-known that to ensure survival and negate the adverse effects of ROS, plants activate the antioxidant enzymes defense system in response to an elevated amount of ROS [49,50]. POD, CAT, APX, and GR are the main components of the enzymatic antioxidant defense system [51] which efficiently scavenge ROS and play an important role in conferring drought stress tolerance [51,52]. CAT is the first line antioxidant enzyme [53], APX and GR are the key components of the Ascorbate-Glutathione (AsA-GSH) pathway which mitigates the harmful effects of ROS [54].…”

Response of Plants to Water Stress: A Meta-Analysis

“…For plants, water limitations lead to the overproduction of reactive oxygen species (ROS), such as hydrogen peroxide (H 2 O 2 ), and superoxide anion radicals (O2 •) which results in growth inhibition (Wallace et al, 2016), decreases in photosynthetic functions (Deeba et al, 2012), lipid peroxidation, and the higher frequency of programmed cell death processes (Gill and Tuteja, 2010). However, to adapt to water stress, plants have evolved many acclimation mechanisms, including osmotic adjustment and antioxidant defense systems, which enhances their capacity to grow and develop under drought conditions (Fu and Huang, 2001;Khaleghi et al, 2019). Under water stress conditions, soluble sugars and proline accumulate to serve as osmolytes in various plants, assist in membrane protein stabilization, and ultimately increase plant resistance against water stress (Ashraf and Foolad, 2007;Gomes et al, 2010;Per et al, 2017).…”