Effects of specific expression of iaaL gene in tobacco tapetum on pollen embryogenesis  

作　　者：杨洪全 卫志明 许智宏 

机构地区：[1]State Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology, Chinese Academy of Sciences, Shanghai 200032, China

出　　处：《Science China(Life Sciences)》1997年第4期384-391,共8页中国科学（生命科学英文版）

基　　金：Project supported by the State Key Laboratory of Plant Molecular Genetics.

摘　　要：The indoleacetic-acid-lysine synthetase (iaaL) gene from Pseudomonas syringae subsp. savastanoi was fused to tobacco tapetum-specific expression promoter TA29, and introduced into tobacco. The expression pattern of this chimeric gene was studied, and the endogenous indoleacetic acid (IAA) levels in different organs were assayed. The results demonstrated that TA29 promoter was only able to direct the specific expression of iaaL gene in transgenic tobacco anther, and resulted in the decrease of endogenous IAA levels in transgenic tobacco anther. No significant phe-notype variation was observed among the transgenic plants at the whole plant level. However, the percentage of pollen embryogenesis was reduced to 11 % when anthers of the transgenic plants were cultured on the modified hormone-free Nistch H (NH) medium, while those of both CK1 and CK2 (see sec. 1.2.2) were more than 50% ; when the an-thers were cultured on NH medium supplemented with 0. 2 mg/L IAA, the percentage of pollen embryogenesis re-stored to the same level of that of the wild type (up to 55. 7% ). This study demonstrates that the IAA metabolism in anther tapetum cells is of significant importance to the androgenic development in anther culture.The indoleacetic-acid-lysine synthetase (iaaL) gene from Pseudomonas syringae subsp. savastanoi was fused to tobacco tapetum-specific expression promoter TA29, and introduced into tobacco. The expression pattern of this chimeric gene was studied, and the endogenous indoleacetic acid (IAA) levels in different organs were assayed. The results demonstrated that TA29 promoter was only able to direct the specific expression of iaaL gene in transgenic tobacco anther, and resulted in the decrease of endogenous IAA levels in transgenic tobacco anther. No significant phe-notype variation was observed among the transgenic plants at the whole plant level. However, the percentage of pollen embryogenesis was reduced to 11 % when anthers of the transgenic plants were cultured on the modified hormone-free Nistch H (NH) medium, while those of both CK1 and CK2 (see sec. 1.2.2) were more than 50% ; when the an-thers were cultured on NH medium supplemented with 0. 2 mg/L IAA, the percentage of pollen embryogenesis

关 键 词：tapetum-specific expression indoleacetic-acid-lysine SYNTHETASE GENE transgenic TOBACCO pollen embryogenesis. 

分 类 号：S572[农业科学—烟草工业]