转Bt基因对水稻内生原核微生物定殖数量效应分析

Quantity effects analysis of Bt genes on the endophytic prokaryotes in transgenic rice

为探讨转Bt基因对水稻内生原核微生物定殖的数量效应,首先确定水稻根、茎、叶表面微生物的消毒时间和条件;其次,在有效排除水稻植株表面微生物干扰的条件下,应用纯培养方法对转Bt基因及其亲本水稻各组织的内生原核微生物定殖数量进行检测分析,初步评估各亲本水稻在引入外源Bt基因后,给水稻植株内生原核微生物数量带来的影响。结果显示,水稻根际微生物以70%乙醇浸泡7 min,茎和叶表面微生物以70%乙醇浸泡2 min,以无菌水漂洗2次,可达到杀灭表面微生物的效果。本次试验中,ZJ-22和明恢63两个水稻品系亲本植株根、茎的内生原核微生物定殖数量,在苗期和分蘖期时均高于对应的转Bt基因植株(ZJ-22Bt和TT51-1);苗期时两个品系亲本水稻叶片内生微生物数量同样高于转Bt基因水稻,分裂期转Bt水稻TT51-1叶片内生原核微生物数量则多于其亲本植株明恢63。以上结果表明,两个品系亲本水稻插入外源基因后,在苗期和分裂期对亲本植株各部位的内生原核微生物定殖情况均产生了一定的影响。

The communities （quantity effects） of endophytie prokaryotes in transgenic and wild-type rice were investigated in the present study. At first, the optimal sterilizing methods for the surface of leaves, stems and roots of rice were investigated and determined as follows： rice roots and the other tissues （stems and leaves） could be sterilized through soaking in 70% ethanol for 7 rain and 2 min, respectively; both ethanol-soaking were followed by washing with distilled water twice. Thereafter, the number of endophytic prokaryotes in the roots, stems and leaves of rice was examined, and the results showed that the number of endophytic prokaryotes in all parts of transgenie rice was less than that of wild-type rice at the seedling stage; the similar results were also observed at the stooling stage, except that in the leaves of transgenic rice TT51-1. The number of endophytic prokaryotes in all parts of rice at stooling stage was higher than that at seedling stage for both transgenic and wild-type rice. Our data showed that Bt gene insertion could significantly affect on the number of endophytic prokaryotes of rices in both of seedling and stooling stages.