Endophytic bacteria in rice seeds inhibit early colonization of roots by Azospirillum brasilense
Endophytic bacteria in rice seeds inhibit early colonization of roots by Azospirillum brasilense
复制标题
DOI：
10.1016/s0038-0717(00)00126-7
复制
发表时间：
2001-02-01
影响因子：
9.7
通讯作者：
Zenteno, E
中科院分区：
文献类型：
--
作者：
Bacilio-Jiménez, M;Aguilar-Flores, S;Zenteno, E
从水稻的根面。瓦尔斯从莫雷洛斯A-88和Apatzingan水稻试管苗中分离到两株细菌：黄色棒状杆菌和短小芽孢杆菌。通过扫描电镜观察，内生细菌多分布在次生根的基部，表皮和粘液层之间。当粘液层被破坏时，在细胞间隙中也鉴定出内生菌。这些内生细菌在烟草叶片上检测时没有致病性。用巴西固氮菌、6-81或UAP-154菌株接种水培水稻品种的试管苗。使用未接种的小植株或先前用萘啶酸处理的小植株进行对照实验。接种或萘啶酸处理的小植株与未接种的小植株的长度的比较揭示了在仅被内生菌定殖的小植株中，在培养15天时芽的生长的显著（p < 0.05）促进。A. brasilense似乎被内生细菌排除在根面之外，这表明内生细菌与固氮菌竞争，同时也表明固氮菌与固氮菌竞争。brasilense抑制水稻的生长。结果表明，内生细菌可能参与水稻的生长发育。(C)2001爱思唯尔科技有限公司版权所有。
From the rhizoplane of Oryza sativa. vars. Morelos A-88 and Apatzingan, rice plantlets, we isolated two bacterial strains: Corynebacterium flavescens and Bacillus pumilus. By scanning electron microscopy, endophytic bacteria were frequently identified at the base of secondary roots, between the epidermis and the mucilaginous layer. Endophytes were also identified in the intercellular spaces when the mucilaginous layer was disrupted. These endophytic bacteria were not pathogenic when assayed on tobacco leaves. Plantlets from the rice varieties cultured gnotobiotically under hydroponic conditions were inoculated with Azospirillum brasilense, 6-81 or UAP-154 strains. Control experiments were performed using non-inoculated plantlets or plantlets previously treated with nalidixic acid. Comparison of the length of inoculated or nalidixic acid-treated plantlets, with non-inoculated plantlets revealed a significant (p < 0.05) promotion of the growth of the shoots at 15 days of culture in plantlets colonized exclusively by endophytes. A. brasilense seems to be excluded from the rhizoplane by the endophytic bacteria, suggesting that endophytes compete with Azospirillum, and also that A. brasilense inhibits growth of rice. Our results indicate that endophytic bacteria could participate in the growth and development of rice plants. (C) 2001 Elsevier Science Ltd. All rights reserved.