We isolated a stamen-specific cDNA, BSD1 (Brassica stamen specific plant defensin 1) that encodes a novel plant defensin peptide in Chinese cabbage (Brassica campestris L. ssp. pekinensis). Plant defensins are antimicrobial peptides containing eight highly conserved cysteine residues linked by disulfide bridges. In BSD1, the eight cysteine residues and a glutamate residue at position 29 are conserved whereas other amino acid residues of the plant defensins consensus sequence are substituted. BSD1 transcripts accumulate specifically in the stamen of developing flowers and its level drops as the flowers mature. The recombinant BSD1 produced in Escherichia coli showed antifungal activity against several phytopathogenic fungi. Furthermore, constitutive over-expression of the BSD1 gene under the control of the cauliflower mosaic virus (CaMV) 35S promoter conferred enhanced tolerance against the Phytophthora parasitica in the transgenic tobacco plants.

中文翻译：

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大白菜中编码新型植物防御素的雄蕊特异性 cDNA 的表征。


我们在大白菜（Brassica Campestris L. ssp. pekinensis）中分离出了雄蕊特异性 cDNA，BSD1（Brassica stamen Specific plant defensin 1），它编码一种新型植物防御素肽。植物防御素是含有八个通过二硫桥连接的高度保守的半胱氨酸残基的抗菌肽。在BSD1中，位置29的八个半胱氨酸残基和谷氨酸残基是保守的，而植物防御素共有序列的其他氨基酸残基被取代。 BSD1 转录本专门在发育中的花的雄蕊中积累，并且其水平随着花的成熟而下降。大肠杆菌中产生的重组 BSD1 对多种植物病原真菌具有抗真菌活性。此外，在花椰菜花叶病毒（CaMV）35S启动子控制下的BSD1基因的组成型过表达增强了转基因烟草植物对寄生疫霉的耐受性。