Beneficial Effects of Biochar and Chitosan on Antioxidative Capacity, Osmolytes Accumulation, and Anatomical Characters of Water-Stressed Barley Plants

Abstract

The impact of biochar and chitosan on barley plants under drought stress conditions was investigated during two field experiments. Our results confirmed that drought stress negatively affected morphological and physiological growth traits of barley plants such as plant height, number of leaves, chlorophyll concentrations, and relative water content. However, electrolyte leakage (EL%), lipid peroxidation (MDA), soluble sugars, sucrose and starch contents significantly increased as a response to drought stress. Additionally, 1000 grain weight, grains yield ha−1 and biological yield significantly decreased in stressed barley plants, also anatomical traits such as upper epidermis, lower epidermis, lamina, and mesophyll tissue thickness as well as vascular bundle diameter of flag leaves significantly decreased compared with control. The use of biochar and chitosan led to significant increases in plant height, number of leaves, and chlorophyll concentrations as well as relative water content; nevertheless these treatments led to significant decreases in electrolyte leakage (EL%) and lipid peroxidation (MDA) in the stressed plants. Moreover, anatomical and yield characters of stressed barley plants were improved with application of biochar and chitosan. The results proved the significance of biochar and chitosan in alleviating the damaging impacts of drought on barley plants.

Chlorophyll Fluorescence Parameters and Antioxidant Defense System Can Display Salt Tolerance of Salt Acclimated Sweet Pepper Plants Treated with Chitosan and Plant Growth Promoting Rhizobacteria

“…Likewise, chitosan application causes an increase in enzymes activity to protect the plant from oxidative damage and reduce lipid peroxidation as well as scavenge O 2 − due to its structure and protective role in sweet pepper plants subjected to salinity stress. These results are in agreement with those reported by Hafez et al [19]. The presented study showed that two salinity concentrations caused a significant reduction in the number of fruit plant −1 , fruit fresh weight plant −1 , and total fruit yield.…”

“…Chitosan application positively affects RWC in stressed plants, this progressive effect of chitosan could be due to the positive role of chitosan on water availability in stressed plants. These valuable effects were documented in barley under drought [19].…”

“…Glycophytes cannot grow under high salinity concentrations and their response to salinity differs in terms of osmotic regulation, photosynthetic electron transport, chlorophyll content, and reactive oxygen species (ROS) formation as well as antioxidant defense system [1,7]. The excessive accumulation of ROS under stress, such as salinity [1,17], drought [18,19], and biotic stress factors [20][21][22][23], results in the activation of the enzymatic and non-enzymatic antioxidant system to enhance stress tolerance in plants to cope with increased accumulation of ROS [24]. The antioxidative system also consists of some of the non-enzymatic systems, such as salicylic acid and carotenoids.…”

Pure Organic Active Compounds Against Abiotic Stress: A Biostimulant Overview

“…Interestingly, this treatment improved antioxidant systems, photosynthesis and grain yield. In barley, chitosan also improved the response to drought stress (Hafez et al, 2020). Zeng and Luo (2012) found that coating wheat seedlings with chitosan improved drought tolerance by influencing physiological mechanisms, such as increasing antioxidant defences and improving chlorophyll content.…”

Ginkgo biloba and Helianthus annuus show different strategies to adjust photosynthesis, leaf water relations, and cell wall composition under water deficit stress

“…Additionally, water deficit stress strongly limited leaf development in both species as LA decreased significantly (Table 1), which has been described as a typical response to water deficit stress (Chaves et al 2002). However, although Chartzoulakis et al (2002) and Hafez et al (2020) reported modifications in leaf, mesophyll, and epidermis thicknesses as well as in fias testing avocado and barley, respectively, under water deprivation, Tomás et al (2014) did not detect strong subcellular anatomical alterations in water-stressed grapevine cultivars. In fact, in the present study neither Tcw nor other subcellular anatomical traits classically affecting gm were modified under water deficit stress (Table 1), suggesting that decreased gm in water-stressed H. annuus might be due to other nonstudied characteristics (e.g., aquaporins and/or carbonic anhydrases, see Pérez-Martín et al 2014).…”