van Kan J A, van't Klooster J W, Wagemakers C A, Dees D C, van der Vlugt-Bergmans C J
Department of Phytopathology, Wageningen Agricultural University, The Netherlands.
Mol Plant Microbe Interact. 1997 Jan;10(1):30-8. doi: 10.1094/MPMI.1997.10.1.30.
The plant pathogen Botrytis cinerea can infect undamaged plant tissue directly by penetration of the cuticle. This penetration has been suggested to be enzyme-mediated, and an important role for cutinase in the infection process has been proposed. In this study the expression of the cutinase encoding gene cutA of B. cinerea was analyzed using a cutA promoter-GUS reporter gene fusion. Transformants containing the fusion construct were examined for GUS expression on gerbera flowers and tomato fruits. High GUS activity was detected from the onset of conidial germination and during penetration into epidermal cells, indicating that cutA is expressed during the early stages of infection. To determine the biological relevance of cutinase A for successful penetration, cutinase A-deficient mutants were constructed by gene disruption. Pathogenicity of two transformants lacking a functional cutA gene was studied on gerbera flowers and tomato fruits. Their ability to penetrate and cause symptoms was unaltered compared to the wild-type strain. These results exclude an important role for cutinase A during direct penetration of host tissue by B. cinerea.
植物病原菌灰葡萄孢可通过穿透角质层直接感染未受损的植物组织。这种穿透作用被认为是由酶介导的，并且有人提出角质酶在感染过程中起重要作用。在本研究中，使用角质酶编码基因cutA的启动子-GUS报告基因融合体分析了灰葡萄孢角质酶编码基因cutA的表达。检测含有融合构建体的转化体在非洲菊花朵和番茄果实上的GUS表达。从分生孢子萌发开始到侵入表皮细胞的过程中均检测到高GUS活性，表明cutA在感染早期表达。为了确定角质酶A对成功穿透的生物学相关性，通过基因破坏构建了角质酶A缺陷型突变体。研究了两个缺乏功能性cutA基因的转化体在非洲菊花朵和番茄果实上的致病性。与野生型菌株相比，它们的穿透和引起症状的能力没有改变。这些结果排除了角质酶A在灰葡萄孢直接穿透宿主组织过程中的重要作用。
