摘要
采用细菌转化和杂交的方法，成功地将全套发光酶基因标记系统Ｔｎ７ｌｕｘＣＤＡＢＥ引入绿针假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｃｈｌｏｒｏｒａｐｈｉｓ）ＰＬ９，得到稳定的发光标记菌ＰＬ９Ｌ。采用发光菌落平板计数法和Ｘ射线胶片自显影法，通过盆栽试验和盒裁试验，研究了发光标记菌ＰＬ９Ｌ在棉花根圈的定殖动态和分布规律。盆栽试验结果表明，在灭菌土盆栽中，播种后６ｄ左右ＰＬ９Ｌ在棉花根圈的定殖水平达最高（３１×１０９ｃｆｕ／ｇ根土），播种后５６ｄ左右趋向稳定，ＰＬ９Ｌ数量为１７×１０２ｃｆｕ／ｇ根土；未灭菌土盆载中，播种后８ｄ左右ＰＬ９Ｌ的定殖水平达最高（１１×１０９ｃｆｕ／ｇ根土），４６ｄ左右趋向稳定，菌数为１４×１０２ｃｆｕ／ｇ根土。盒栽试验结果表明，ＰＬ９Ｌ可从种子向根尖方向扩散，但并不与根的伸长生长同步，播种后３６ｄ，灭菌土盒栽中ＰＬ９Ｌ可扩散至种子下方１２０ｃｍ以内，而未灭菌土盒栽中ＰＬ９Ｌ扩散至１１０ｃｍ以内。在棉花根尖区域均未检测到ＰＬ９Ｌ。
Tn7 luxCDABE marker system was successfully transferred into Pseudomonas chlororaphis (strain PL9)by means of transformation and conjugation and a stable lux marked strain PL9L was obtained.The colonizing dynamics and distribution of the luminescent bacteria PL9L in the rhizosphere of cotton planted in pots and rhizoboxes were studied by the methods of X ray film imaging and enumeration of luminescent colonies on agar media,The results of pot culture experiment showed that PL9L successfully colonized in the rhizosphere of cotton.In pot cultures of sterile soil the highest colonizing level(3 1×10 2 cfu/g root soil)was reached on 6th day after seeds sown;On 56th day,the population of PL9L tended to stable and decreased to 1 7×10 9 cfu/g root soil)but in pot cultures of unsterile soil, the highest cdonizing leovel(1 1×10 9 cfu/g root soil) was reached on 8th day.On 46th day,the population of PL9L tended to a stationary state,the numbers of them were 1 4×10 2 cfu/g root soil.The results of rhizobox culture experiment showed that PL9L spread from seeds toward the dirction of root tip,but not synchronized with the stretch of roots.6 days after seeds sown, in rhizobox culture of sterile soil,PL9L spread 12 0cm below seeds,but in non sterile soil was 11 0cm.In the region of cotton root tip,PL9L were not detected.
出处
《微生物学报》
CAS
CSCD
北大核心
1999年第1期43-48,共6页
Acta Microbiologica Sinica
基金
国家自然科学基金
关键词
发光酶标记基因
绿叶假单胞菌
棉花根圈
定殖动态
Tn5 luxCDABE genes, Pseudomonas chlororaphis, Cotton rhizosphere,Colonizing Dynamics.
