Shankar Ajay, Prasad Vishal
Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India.
Front Microbiol. 2023 Feb 8;14:1017167. doi: 10.3389/fmicb.2023.1017167. eCollection 2023.
Wheat ( L.) yield and physiology are adversely affected due to limited water availability. However, desiccation-tolerant plant growth-promoting rhizobacteria (DT-PGPR) are potential candidates that can overcome the negative impacts of water stress. In the present study, a total of 164 rhizobacterial isolates were screened for desiccation tolerance up to -0.73 MPa osmotic pressure, of which five isolates exhibited growth and expression of plant growth properties under the influence of desiccation stress of -0.73 MPa. These five isolates were identified as BHUAS1, BHUAS2, BHUIESDAS3, BHUIESDAS4, and BHUIESDAS5. All five isolates exhibited plant growth-promoting properties and production of exopolysaccharide (EPS) under the impact of desiccation stress. Furthermore, a pot experiment on wheat (variety HUW-234) inoculated with the isolates BHUAS1, BHUAS2, and BHUIESDAS3 exhibited a positive influence on the growth of wheat under the condition of water stress. A significant improvement in plant height, root length, biomass, chlorophyll and carotenoid content, membrane stability index (MSI), leaf relative water content (RWC), total soluble sugar, total phenol, proline, and total soluble protein, were recorded under limited water-induced drought stress in treated plants as compared with non-treated plants. Moreover, plants treated with BHUAS1, BHUAS2, and BHUIESDAS3 depicted improvement in enzymatic activities of several antioxidant enzymes such as guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Beside this significant decrease in electrolyte leakage, HO and malondialdehyde (MDA) contents were also recorded in treated plants. From the results obtained, it is evident that . BHUAS1, . BHUIESDAS3, and . BHUAS2 are the potential DT-PGPR having the capability to sustain growth and yield, alleviating the deleterious effect of water stress in wheat.
由于可用水分有限，小麦（L.）的产量和生理机能受到不利影响。然而，耐旱植物促生根际细菌（DT-PGPR）是可以克服水分胁迫负面影响的潜在候选者。在本研究中，总共筛选了164株根际细菌分离株对高达-0.73 MPa渗透压的耐旱性，其中五株分离株在-0.73 MPa的干旱胁迫影响下表现出植物生长特性的生长和表达。这五株分离株被鉴定为BHUAS1、BHUAS2、BHUIESDAS3、BHUIESDAS4和BHUIESDAS5。所有五株分离株在干旱胁迫影响下均表现出植物促生特性和胞外多糖（EPS）的产生。此外，对接种了分离株BHUAS1、BHUAS2和BHUIESDAS3的小麦（品种HUW-234）进行的盆栽试验表明，在水分胁迫条件下对小麦生长有积极影响。与未处理的植株相比，在有限水分诱导的干旱胁迫下，处理过的植株在株高、根长、生物量、叶绿素和类胡萝卜素含量、膜稳定性指数（MSI）、叶片相对含水量（RWC）、总可溶性糖、总酚、脯氨酸和总可溶性蛋白方面有显著改善。此外，用BHUAS1、BHUAS2和BHUIESDAS3处理的植株在几种抗氧化酶如愈创木酚过氧化物酶（POD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的酶活性方面有所提高。除此之外，处理过的植株中电解质渗漏、HO和丙二醛（MDA）含量也显著降低。从获得的结果来看，很明显BHUAS1、BHUIESDAS3和BHUAS2是具有维持生长和产量能力的潜在DT-PGPR，可减轻小麦水分胁迫的有害影响。
