Talaat Neveen B, Shawky Bahaa T
Department of Plant Physiology, Faculty of Agriculture, Cairo University, Giza 12613, Egypt.
Department of Microbial Chemistry, Biotechnology Research Institute, National Research Centre, Giza 12311, Egypt.
Plants (Basel). 2022 Feb 2;11(3):416. doi: 10.3390/plants11030416.
Salicylic acid (SA) and melatonin (MT) have been shown to play important roles in plant salt tolerance. However, the underlying mechanisms of SA-MT-interaction-mediated ionic homeostasis in salt-stressed plants are unknown. As a first investigation, this study aimed to clarify how SA-MT interaction affects H-pump activity in maintaining the desired ion homeostasis under saline conditions and its relation to ROS metabolism. Wheat ( L.) plants were grown under non-saline or saline conditions and were foliar sprayed with 75 mg L SA or 70 μM MT. The SA+MT combined treatment significantly increased N, P, K, Fe, Zn, and Cu acquisition, accompanied by significantly lower Na accumulation in salt-stressed plants compared to non-stressed ones. Additionally, it significantly enhanced ATP content and H-pump activity of the roots. The mitigation was also detected in the reduced superoxide radical content, electrolyte leakage, and lipoxygenase activity, as well as increased superoxide dismutase, catalase, peroxidase, and polyphenol oxidase activities; K/Na, Ca/Na, and Mg/Na ratios; relative water content; membrane stability index; and free amino acid accumulation in treated plants. The novel evidence shows that the higher root H-pump activity in treated plants is a tolerance mechanism that increases the salt tolerance via maintaining ionic homeostasis.
水杨酸（SA）和褪黑素（MT）已被证明在植物耐盐性中发挥重要作用。然而，盐胁迫植物中SA - MT相互作用介导的离子稳态的潜在机制尚不清楚。作为首次研究，本研究旨在阐明SA - MT相互作用如何影响H⁺泵活性以在盐胁迫条件下维持所需的离子稳态及其与活性氧代谢的关系。小麦（Triticum aestivum L.）植株在非盐或盐胁迫条件下生长，并叶面喷施75 mg L⁻¹ SA或70 μM MT。与未胁迫植株相比，SA + MT组合处理显著增加了盐胁迫植株对氮、磷、钾、铁、锌和铜的吸收，同时显著降低了钠的积累。此外，它还显著提高了根系的ATP含量和H⁺泵活性。在处理植株中还检测到超氧阴离子含量降低、电解质渗漏和脂氧合酶活性降低，以及超氧化物歧化酶、过氧化氢酶、过氧化物酶和多酚氧化酶活性增加；钾/钠、钙/钠和镁/钠比值；相对含水量；膜稳定性指数；以及游离氨基酸积累等缓解现象。新的证据表明，处理植株中较高的根系H⁺泵活性是一种通过维持离子稳态来提高耐盐性 的耐受机制。
