Chen Enni, Yang Changsheng, Tao Weiyi, Li Shuang
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China.
College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, China.
Polymers (Basel). 2024 Jan 3;16(1):145. doi: 10.3390/polym16010145.
Salt stress is one of the most serious abiotic stresses leading to reduced agricultural productivity. Polysaccharides from seaweed have been used as biostimulants to promote crop growth and improve plant resistance to abiotic stress. In this study, PGPR strain sp. BK01 was isolated from the rhizosphere of wheat, and it was characterized for phosphorus (Pi) dissolution, indole-3-acetic acid (IAA) production, ammonia (NH) and exopolysaccharides (EPS). In particular, strain BK01 can efficiently produce extracellular polysaccharide with a yield of 12.86 g/L, using sorbitol as carbon source. BK01 EPS was identified as an heteropolysaccharide with Mw 3.559 × 10 Da, composed of (D)-galactose (75.3%), (D)-glucose (5.5%), (L)-rhamnose (5.5%), (D)-galactouronic acid (4.9%) and (D)-glucuronic acid (8.8%). The present work aims to highlight the effect of the BK01 EPS on growth and biochemical changes in under salt stress (100 mM). The purified BK01 EPS at a concentration of 100 mg/L efficiently promoted the growth of plants in pot assays, improved the chlorophyll content, enhanced the activities of SOD, POD and CAT, and decreased the content of MDA. This results suggested that the polysaccharides produced by PGPR strain sp. BK01 can be used as biostimulants to promote plant growth and improve plant resistance to salt stress.
盐胁迫是导致农业生产力下降的最严重非生物胁迫之一。海藻多糖已被用作生物刺激剂，以促进作物生长并提高植物对非生物胁迫的抗性。在本研究中，从小麦根际分离出PGPR菌株sp. BK01，并对其溶解磷（Pi）、产生吲哚-3-乙酸（IAA）、氨（NH）和胞外多糖（EPS）的特性进行了表征。特别是，菌株BK01可以有效地产生胞外多糖，以山梨醇为碳源时产量为12.86 g/L。BK01 EPS被鉴定为一种分子量为3.559×10 Da的杂多糖，由（D）-半乳糖（75.3%）、（D）-葡萄糖（5.5%）、（L）-鼠李糖（5.5%）、（D）-半乳糖醛酸（4.9%）和（D）-葡萄糖醛酸（8.8%）组成。本研究旨在突出BK01 EPS对盐胁迫（100 mM）下植物生长和生化变化的影响。在盆栽试验中，浓度为100 mg/L的纯化BK01 EPS有效地促进了植物生长，提高了叶绿素含量，增强了超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性，并降低了丙二醛（MDA）含量。这些结果表明，PGPR菌株sp. BK01产生的多糖可以用作生物刺激剂来促进植物生长并提高植物对盐胁迫的抗性。
