Lastochkina Oksana, Ivanov Sergey, Petrova Svetlana, Garshina Darya, Lubyanova Alsu, Yuldashev Ruslan, Kuluev Bulat, Zaikina Evgenia, Maslennikova Dilara, Allagulova Chulpan, Avtushenko Irina, Yakupova Albina, Farkhutdinov Rashit
Institute of Biochemistry and Genetics UFRC RAS, 71 Pr. Oktyabrya, 450054 Ufa, Russia.
Ufa Institute of Chemistry UFRC RAS, 69 Pr. Oktyabrya, 450054 Ufa, Russia.
Plants (Basel). 2022 Dec 3;11(23):3365. doi: 10.3390/plants11233365.
Endophytic is a non-pathogenic beneficial bacterium which promotes plant growth and tolerance to abiotic stresses, including drought. However, the underlying physiological mechanisms are not well understood. In this study, the potential role that endogenous salicylic acid (SA) plays in regulating endophytic -mediated drought tolerance in wheat ( L.) was examined. The study was conducted on genotypes with contrasting levels of intrinsic drought tolerance (drought-tolerant (DT) cv. Ekada70; drought-susceptible (DS) cv. Salavat Yulaev). It was revealed that 10-4 promoted endogenous SA accumulation and increased the relative level of transcripts of the gene, a marker of the SA-dependent defense pathway, but two wheat cultivars responded differently, with the highest levels exhibited in DT wheat seedlings. These had a positive correlation with the ability of strain 10-4 to effectively protect DT wheat seedlings against drought injury by decreasing osmotic and oxidative damages (i.e., proline, water holding capacity (WHC), and malondialdehyde (MDA)). However, the use of the SA biosynthesis inhibitor 1-aminobenzotriazole prevented endogenous SA accumulation under normal conditions and the maintenance of its increased level under stress as well as abolished the effects of treatment. Particularly, the suppression of strain 10-4-induced effects on proline and WHC, which are both contributing factors to dehydration tolerance, was found. Moreover, the prevention of strain 10-4-induced wheat tolerance to the adverse impacts of drought, as judged by the degree of membrane lipid peroxidation (MDA) and plant growth (length, biomass), was revealed. Thus, these data provide an argument in favor of a key role of endogenous SA as a hormone intermediate in triggering the defense responses by 10-4, which also afford the foundation for the development of the bacterial-induced tolerance of these two different wheat genotypes under dehydration.
内生菌是一种非致病性有益细菌，可促进植物生长并提高其对包括干旱在内的非生物胁迫的耐受性。然而，其潜在的生理机制尚未完全清楚。在本研究中，研究了内源性水杨酸（SA）在调节小麦内生菌介导的耐旱性中所起的潜在作用。该研究针对具有不同内在耐旱水平的基因型（耐旱（DT）品种Ekada70；干旱敏感（DS）品种Salavat Yulaev）进行。结果表明，10-4促进了内源性SA的积累，并增加了SA依赖防御途径的标记基因的转录本相对水平，但两个小麦品种的反应不同，DT小麦幼苗中表现出的水平最高。这些与菌株10-4通过降低渗透和氧化损伤（即脯氨酸、持水能力（WHC）和丙二醛（MDA））有效保护DT小麦幼苗免受干旱伤害的能力呈正相关。然而，使用SA生物合成抑制剂1-氨基苯并三唑可防止正常条件下内源性SA的积累以及胁迫下其升高水平的维持，并消除了10-4处理的效果。特别是，发现抑制了菌株10-4对脯氨酸和WHC的诱导作用，而脯氨酸和WHC都是耐旱性的促成因素。此外，通过膜脂过氧化程度（MDA）和植物生长（长度、生物量）判断，揭示了阻止菌株10-4诱导的小麦对干旱不利影响的耐受性。因此，这些数据支持内源性SA作为激素中间体在触发10-4防御反应中起关键作用的观点，这也为这两种不同小麦基因型在脱水条件下细菌诱导耐受性的发展提供了基础。
