Physiological response of mango transplants to phytohormones under salinity stress

Exogenous naphthaleneacetic acid alleviated alkalinity-induced morpho-physio-biochemical damages in Cyperus esculentus L. var. sativus Boeck

“…Compared to unsprayed chufa plants, NAA increased chlorophyll concentrations under controlled and alkaline stress conditions. Several studies have shown that NAA reduces the damage caused to chlorophyll pigments in leaves by saline-alkaline stress, which is in agreement with our findings ( Burondkar et al., 2009 ; Abou El-ghit, 2015 ; Ullah and Sajjad, 2017 ; Muhammed et al., 2022 ). Importantly, NAA-induced restoration of chlorophyll pigments in the alkaline-stressed chufa plants exhibited an osmoprotective and membrane-protective role of NAA for chufa plants subjected to alkalinity.…”

“…In contrast, NAA application significantly inhibited the accumulation of H 2 O 2 and MDA, but increased activity of antioxidant enzymes including SOD, CAT and POD in alkalinity-stressed chufa plants compared with control plants and alkalinity-treated plants alone, suggesting that NAA activated adaptive mechanisms against oxidative damages in stressed plants. These findings demonstrate that NAA-application increased antioxidant activity to protect chufa plants against oxidative damage associated with alkalinity, as evidenced by the observed decrease in MDA concentration, which are in line with previous studies ( Olaiya & Anyanwu, 2013 ; Ullah & Sajjad, 2017 ; Khedr et al., 2022 ; Muhammed et al., 2022 ). We suggest that chufa plant is able to significantly increase the activity of antioxidant enzymes in order to resist alkaline stress.…”

“…NAA, similar to naturally occurring IAA stimulates cell division, and cell elongation leading to increased growth. Consequently, the results of the current study and previously published reports indicate that NAA provides protection against a wide variety of environmental stresses (Zhou et al, 2012;Abou El-ghit, 2015;Ullah & Sajjad, 2017;Muhammed et al, 2022).…”

“…In contrast, NAA-applied chufa plants significantly decreased Na + and Cl - concentrations while improving Mg 2+ , K + , and K + /Na + ratios in both roots and leaves. Previous studies reported that IAA and NAA reduced the Na + accumulation and enhanced K + , Ca +2 , and P contents in plants grown under salinity conditions ( Kaya et al., 2010 ; Olaiya and Anyanwu, 2013 ; Muhammed et al., 2022 ). Therefore, we propose that NAA application ameliorated the adversity of alkalinity on C. esculentus by declining the toxic accumulations of salt ions and increasing beneficial mineral nutrients (i.e., K + , Mg 2+ ) to optimize its cellular metabolism and growth.…”

“…Plant growth regulators, whether natural or synthetic, affect endogenous hormonal patterns in the plant, either by supplementing sub-optimal levels or by interfering with their synthesis, translocation, or inactivation ( Basuchaudhuri, 2016 ). Foliar application of plant growth regulators, including NAA, have been reported to increase, plant photosynthesis, ions regulation and anti-oxidant defense mechanism and hence protect plant tissues from salinity-induced damages ( Ullah and Sajjad, 2017 ; Muhammed et al., 2022 ). However, our understanding of the role of exogenous NAA application in alleviating the alkalinity-induced physio-biochemical responses of plants is sparse, and needs further investigation.…”