Hu Wentao, Zhang Haoqiang, Chen Hui, Tang Ming
College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
College of Forestry, Northwest A&F University, Yangling, Shaanxi, 712100, People's Republic of China.
Mycorrhiza. 2017 Jul;27(5):451-463. doi: 10.1007/s00572-017-0765-0. Epub 2017 Feb 9.
Arbuscular mycorrhizal (AM) fungi can assist their hosts to cope with water stress and other abiotic stresses in different ways. In order to test whether AM plants have a greater capacity than control plants to cope with water stress, we investigated the water status and photosynthetic capacity of Lycium barbarum colonized or not by the AM fungus Rhizophagus irregularis under three water conditions during a hot summer. Sugar levels and transcriptional responses of both plant and AM fungus aquaporin genes in roots were analyzed. Compared with control plants, AM plants increased transpiration rate and stomatal conductance but decreased leaf relative water content under moderate water stress. Severe water stress, however, did not inhibit the quantum yield of PSII photochemistry in AM plants versus control plants. AM plants had higher expression levels of plasma membrane intrinsic proteins or tonoplast intrinsic proteins and Rir-AQP2 and lower leaf temperature than control plants under dry-hot stress. Additionally, AM plant sugar levels under normal water conditions were similar to those of control plants under moderate water stress, but sugar levels of AM plants especially increased with severe water stress. When these aspects of performance of AM and control plants under different water conditions are compared overall, AM plants displayed an obvious superiority over control plants at coping with moderate water stress in the hot environment; AM plants maintained normal photochemical processes under severe water stress, while sugar levels were affected strongly.
丛枝菌根(AM)真菌可以通过不同方式帮助其宿主应对水分胁迫和其他非生物胁迫。为了测试AM植物是否比对照植物具有更强的应对水分胁迫的能力,我们在炎热的夏季三种水分条件下,研究了接种或未接种AM真菌不规则球囊霉的枸杞的水分状况和光合能力。分析了根中植物和AM真菌水通道蛋白基因的糖水平和转录反应。与对照植物相比,在中度水分胁迫下,AM植物的蒸腾速率和气孔导度增加,但叶片相对含水量降低。然而,重度水分胁迫并未抑制AM植物与对照植物相比的PSII光化学量子产率。在干热胁迫下,AM植物的质膜内在蛋白或液泡膜内在蛋白以及Rir-AQP2的表达水平高于对照植物,且叶片温度较低。此外,正常水分条件下AM植物的糖水平与中度水分胁迫下对照植物的糖水平相似,但AM植物的糖水平在重度水分胁迫下尤其增加。当总体比较AM植物和对照植物在不同水分条件下的这些性能方面时,AM植物在炎热环境中应对中度水分胁迫方面表现出明显优于对照植物的优势;AM植物在重度水分胁迫下维持正常的光化学过程,而糖水平受到强烈影响。