Interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via promoting proton motive force and reducing proton gradient in alfalfa

Abstract

Background In acidic soils, aluminum (Al) competing with Zn results in Zn deficiency in plants. Zn is essential for auxin biosynthesis. Zn-mediated alleviation of Al toxicity has been rarely studied, the mechanism of Zn alleviation on Al-induced photoinhibition in photosystems remains unclear. The objective of this study was to investigate the effects of Zn and IAA on photosystems of Al-stressed alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or100 μM AlCl3 combined with 0 or 50 μM ZnCl2, and then foliar spray with water or 6 mg L− 1 IAA. Results Our results showed that Al stress significantly decreased plant growth rate, net photosynthetic rate (Pn), quantum yields and electron transfer rates of PSI and PSII. Exogenous application of Zn and IAA significantly alleviated the Al-induced negative effects on photosynthetic machinery, and an interaction of Zn and IAA played an important role in the alleviative effects. After removing apical buds of Al-stressed alfalfa seedlings, the values of pmf, gH+ and Y(II) under exogenous spraying IAA were significantly higher, and ΔpHpmf was significantly lower in Zn addition than Al treatment alone, but the changes did not occur under none spraying IAA. The interaction of Zn and IAA directly increased Y(I), Y(II), ETRI and ETRII, and decreased O2− content of Al-stressed seedlings. In addition, the transcriptome analysis showed that fourteen functionally noted genes classified into functional category of energy production and conversion were differentially expressed in leaves of alfalfa seedlings with and without apical buds. Conclusion Our results suggest that the interaction of zinc and IAA alleviate aluminum-induced damage on photosystems via increasing pmf and decreasing ΔpHpmf between lumen and stroma.

Downregulation of Zn-transporters along with Fe and redox imbalance causes growth and photosynthetic disturbance in Zn-deficient tomato

“…Furthermore, the increase of DIo/RC suggests that Zn-deficiency results in ineffective energy management, which is correlated with the reduced photosynthetic efficiency in leaves of Zn-deprived tomato. Zn functions during photosynthesis when CO 2 is fixed, although chloroplast and photosynthesis can be impaired under deficiency 36,37 . Several cellular dysfunctions and damages related to plant abiotic stress.…”

Nitrogen Attenuated Zinc-Mediated Promotion of Rice Tillering Under Low Temperature via Regulating Auxin and Cytokinin Balance

“…At the same time, Zn can also improve the resistance of plants to abiotic stress by scavenging reactive oxygen species. Studies have shown that Zn plays important roles under drought, heavy metal, salinity, and UV stresses Su et al 2020;Tufail et al 2018). However, the effect of Zn on rice resistance to low temperature is still unclear.…”

“…Zinc (Zn), one of the essential micronutrients for plant growth and development, plays a fundamental role in several critical cellular functions, such as protein metabolism, gene expression, structural and functional integrity of the biomembranes, and photosynthetic carbon metabolism (Cakmak 2000;Cakmak et al 2010a;Marschner 1995). Under abiotic stress conditions, Zn acts as the metal component of copper/zinc-superoxide dismutase (SOD) and can scavenge O 2 − • to control reactive oxygen species (ROS) production, thus resulting in less damage to cell membranes and enhanced plant stress tolerance (Rehman et al 2012;Su et al 2020). The absorption of Zn by plants is a process of thermodynamic passive transmembrane absorption.…”

“…Increasing Zn application can alleviate the damage to plants caused by stress, such as salinity and drought, by regulating the osmotic balance, the antioxidant defense system and avonoid concentrations etc. (Rameshraddy et al 2017;Su et al 2020;Tufail et al 2018).…”

“…yield(Liu et al 2019). Zn is an essential element in rice tillering development and it can enhance plant resistance to abiotic stress, its uptake and utilization by rice is closely related to N status in the environment(Nie et al 2019b;Su et al 2020). However, the effect of Zn on low temperature resistance and tiller recovery is still unclear, especially the effect of the N supply concentration on the process by which Zn affects tiller growth and recovery.Zn improved rice low temperature resistance and accelerated tillering recovery at normal N level Studies have shown that exposure to a low temperature (15°C) during the early stage of growth could damage rice plants (Reddy et al 2021), exposure to 12°C could reduce seedling biomass, inhibit nutrient uptake, and decrease the number of tillers (Liu et al 2019).…”