Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, Ave. Francisco Salazar, 01145, Temuco, Chile.
Laboratorio de Ecología Microbiana Aplicada (EMALAB), Departamento de Ciencias Química y Recursos Naturales, Universidad de La Frontera, Ave. Francisco Salazar, 01145, Temuco, Chile.
Sci Rep. 2021 Jul 2;11(1):13745. doi: 10.1038/s41598-021-93303-8.
Tomato (Solanum lycopersicum L.) is an important vegetable cultivated around the world. Under field conditions, tomato can be negatively affected by water scarcity in arid and semiarid regions. The application of native plant growth-promoting rhizobacteria (PGPR) isolated from arid environments has been proposed as an inoculant to mitigate abiotic stresses in plants. In this study, we evaluated rhizobacteria from Cistanthe longiscapa (syn Calandrinia litoralis and Calandrinia longiscapa), a representative native plant of flowering desert (FD) events (Atacama Desert, Chile), to determine their ability to reduce water scarcity stress on tomato seedlings. The isolated bacterial strains were characterized with respect to their PGPR traits, including P solubilization, 1-aminocyclopropane-1-carboxylate deaminase activity, and tryptophan-induced auxin and exopolysaccharide production. Three PGPR consortia were formulated with isolated Bacillus strains and then applied to tomato seeds, and then, the seedlings were exposed to different levels of water limitations. In general, tomato seeds and seedlings inoculated with the PGPR consortia presented significantly (P ≤ 0.05) greater plant growth (48 to 60 cm of height and 171 to 214 g of weight) and recovery rates (88 to 100%) compared with those without inoculation (37 to 51 cm of height; 146 to 197 g of fresh weight; 54 to 92% of recovery) after exposure to a lack of irrigation over different time intervals (24, 72 and 120 h) before transplantation. Our results revealed the effectiveness of the formulated PGPR consortia from FD to improve the performance of inoculated seeds and seedlings subjected to water scarcity; thus, the use of these consortia can represent an alternative approach for farmers facing drought events and water scarcity associated with climate change in semiarid and arid regions worldwide.
番茄（Solanum lycopersicum L.）是一种在世界各地广泛种植的重要蔬菜。在田间条件下，番茄可能会受到干旱和半干旱地区水资源短缺的负面影响。从干旱环境中分离出的土著植物促生根际细菌（PGPR）被提议作为一种接种剂，以减轻植物的非生物胁迫。在这项研究中，我们评估了来自开花沙漠（FD）事件（智利阿塔卡马沙漠）代表性乡土植物长苞狸藻（Cistanthe longiscapa，即 Calandrinia litoralis 和 Calandrinia longiscapa）的根际细菌，以确定它们减少番茄幼苗水分胁迫的能力。分离的细菌菌株的特征在于其 PGPR 特性，包括 P 溶磷、1-氨基环丙烷-1-羧酸脱氨酶活性、色氨酸诱导的生长素和胞外多糖的产生。用分离的芽孢杆菌菌株配制了三个 PGPR 共生体，然后将其应用于番茄种子，然后将幼苗暴露在不同水平的水分限制下。一般来说，用 PGPR 共生体接种的番茄种子和幼苗的植物生长（高度 48 至 60cm 和重量 171 至 214g）和恢复率（88 至 100%）明显高于未接种的（高度 37 至 51cm；鲜重 146 至 197g；恢复率 54 至 92%），在移植前，不同时间间隔（24、72 和 120h）缺乏灌溉暴露后。我们的结果表明，来自 FD 的配方 PGPR 共生体可有效提高接种种子和幼苗在水分胁迫下的性能；因此，在半干旱和干旱地区，这些共生体的使用可以作为农民应对与气候变化相关的干旱事件和水资源短缺的一种替代方法。
