真空渗入转化法中农杆菌在植株体内的分布和活力变化

以真空渗入处理后的白菜植株为材料，采用组织化学染色法和细菌平板培养的方法，研究了农杆菌在植株体内的分布特点及其活力变化。结果表明：不同器官中农杆菌的分布量不同，以花器官中分布最多，叶中次之，茎中最少；农杆菌存在于细胞间隙中，维管束及其周围分布较集中，在胚珠中大量分布。处理后植株体内，各器官中农杆菌的生活力及其数量都随时间延长而减少，但是花器官中的农杆菌存活量较大，处理15d后的花蕾中仍然有一定量(约10.3个CFU/g组织)具有活力的农杆菌存在。讨论了这些研究结果在揭示真空渗入转化法的转化过程和提高转化频率中的意义。

The distribution and viability changes of the Agrobacteria in the vacuum infiltrated plants of Chinese cabbage

To understand further the mechanism of agrobacteria transformation by vacuum infiltration, the distribution and viability changes of the agrobacteria in infiltrated Chinese cabbage(B. rapa ssp. chinesis) plants were investigated by histochemical staining and bacteria plating techniques. Results revealed that there were different quantities of Agrobacteria in different organs, among which the most quantity occurred in flowers, especially in ovules. The Agrobacteria lied in the space between cells and concentrated in the vascular bundle no matter the type of the organs examined. The CFUs (colony forming unit) of the Agrobacteria derived from the flowers were always the most in every experiment. The viabilities of the agrobacteria in the plants declined dramatically along with the elongation of the time after plant infiltration in all organs, but there were still 103 CFUs per gram fresh tissue in the flowers after 15 days of infiltration. These results may explain the fact that the ovules were the targets for the Agrobacteria mediated vacuum infiltration transformation.