Santos Silvana Gomes Dos, Silva Paula Renata Alves da, Garcia Andres Calderin, Zilli Jerri Édson, Berbara Ricardo Luis Louro
Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil.
Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil.
Braz J Microbiol. 2017 Apr-Jun;48(2):333-341. doi: 10.1016/j.bjm.2016.09.018. Epub 2016 Dec 27.
Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency.
非生物胁迫是限制植物生长发育和生产力的主要因素之一，因此识别能够提高植物胁迫耐受性的微生物具有重要意义。深色有隔内生菌可以成为植物的共生体。在本研究中，我们评估了深色有隔内生菌分离株减轻水稻品种日本晴和皮奥伊水分胁迫影响的能力。实验在无菌条件下进行，水分胁迫由聚乙二醇（PEG）诱导。从巴西亚马逊地区采集的野生稻（Oryza glumaepatula）根部分离出四种深色有隔内生菌。测量了株高以及地上部和根部的鲜重和干重。还测定了叶片蛋白质浓度和抗氧化酶活性。深色有隔内生菌在含有培养基的培养皿中进行体外培养；它们对盐度和水分胁迫表现出不同程度的耐受性。所测试的两个水稻品种对接种深色有隔内生菌的反应不同。内生菌在有水分亏缺和无水分亏缺的情况下均促进了水稻植株的生长。几乎在所有接种处理中都观察到，接种后植物的氧化应激降低，这表现为抗氧化酶活性的下降。结果表明，深色有隔内生真菌提高了水稻植株对缺水胁迫的耐受性。
