NtKTI1, a Kunitz trypsin inhibitor with antifungal activity from Nicotiana tabacum, plays an important role in tobacco's defense response
NtKTI1, a Kunitz trypsin inhibitor with antifungal activity from Nicotiana tabacum, plays an important role in tobacco's defense response
复制标题
NtKTI1 是一种来自烟草的具有抗真菌活性的 Kunitz 胰蛋白酶抑制剂，在烟草的防御反应中发挥着重要作用
DOI：
10.1111/j.1742-4658.2010.07803.x
复制
发表时间：
2010-10-01
期刊：
影响因子：
5.4
通讯作者：
Zheng, Cheng-Chao
中科院分区：
文献类型：
--
作者：
Huang, Hao;Qi, Sheng-Dong;Zheng, Cheng-Chao
构建了接种立枯丝核菌的烟草的cDNA文库，并通过差异杂交筛选鉴定了多个cDNA片段。一个被显着抑制的 cDNA 克隆 NtKTI1 被确认为 Kunitz 植物蛋白酶抑制剂家族的成员。 RT-PCR分析显示NtKTI1在全株中组成型表达，并优先在根和茎中表达。此外，RT-PCR分析表明，在接种立枯丝核菌、机械性损伤和水杨酸处理后，NtKTI1表达受到抑制，但不受茉莉酸甲酯、脱落酸和氯化钠处理的影响。体外试验表明，NtKTI1 对立枯丝核菌具有显着的抗真菌活性，对黑根霉和寄生疫霉具有中等的抗真菌活性。烟草亚科。转基因烟草的生物测定表明，NtKTI1的过表达显着增强了烟草对立枯丝核菌的抗性，并且反义品系比对照品系对植物病原体表现出更高的敏感性。总而言之，这些研究表明 NtKTI1 可能是一种功能性 Kunitz 胰蛋白酶抑制剂，对烟草防御反应中的几种重要植物病原体具有抗真菌活性。
A cDNA library from tobacco inoculated with Rhizoctonia solani was constructed, and several cDNA fragments were identified by differential hybridization screening. One cDNA clone that was dramatically repressed, NtKTI1, was confirmed as a member of the Kunitz plant proteinase inhibitor family. RT-PCR analysis revealed that NtKTI1 was constitutively expressed throughout the whole plant and preferentially expressed in the roots and stems. Furthermore, RT-PCR analysis showed that NtKTI1 expression was repressed after R. solani inoculation, mechanical wounding and salicylic acid treatment, but was unaffected by methyl jasmonate, abscisic acid and NaCl treatment. In vitro assays showed that NtKTI1 exerted prominent antifungal activity towards R. solani and moderate antifungal activity against Rhizopus nigricans and Phytophthora parasitica var. nicotianae. Bioassays of transgenic tobacco demonstrated that overexpression of NtKTI1 enhanced significantly the resistance of tobacco against R. solani, and the antisense lines exhibited higher susceptibility than control lines towards the phytopathogen. Taken together, these studies suggest that NtKTI1 may be a functional Kunitz trypsin inhibitor with antifungal activity against several important phytopathogens in the tobacco defense response.