Salzman R A, Tikhonova I, Bordelon B P, Hasegawa P M, Bressan R A
Center for Plant Environmental Stress Physiology, Purdue University, 1165 Horticulture Building, West Lafayette, Indiana 47907-1165, USA.
Plant Physiol. 1998 Jun;117(2):465-72. doi: 10.1104/pp.117.2.465.
During ripening of grape (Vitis labruscana L. cv Concord) berries, abundance of several proteins increased, coordinately with hexoses, to the extent that these became the predominant proteins in the ovary. These proteins have been identified by N-terminal amino acid-sequence analysis and/or function to be a thaumatin-like protein (grape osmotin), a lipid-transfer protein, and a basic and an acidic chitinase. The basic chitinase and grape osmotin exhibited activities against the principal grape fungal pathogens Guignardia bidwellii and Botrytis cinerea based on in vitro growth assays. The growth-inhibiting activity of the antifungal proteins was substantial at levels comparable to those that accumulate in the ripening fruit, and these activities were enhanced by as much as 70% in the presence of 1 m glucose, a physiological hexose concentration in berries. The simultaneous accumulation of the antifungal proteins and sugars during berry ripening was correlated with the characteristic development of pathogen resistance that occurs in fruits during ripening. Taken together, accumulation of these proteins, in combination with sugars, appears to constitute a novel, developmentally regulated defense mechanism against phytopathogens in the maturing fruit.
在葡萄（美洲葡萄康科德品种）浆果成熟过程中，几种蛋白质的丰度增加，与己糖协同增加，以至于这些蛋白质成为子房中的主要蛋白质。这些蛋白质已通过N端氨基酸序列分析和/或功能鉴定为类甜蛋白（葡萄渗透素）、脂质转移蛋白、一种碱性几丁质酶和一种酸性几丁质酶。基于体外生长试验，碱性几丁质酶和葡萄渗透素对主要的葡萄真菌病原体葡萄球座菌和灰葡萄孢表现出活性。抗真菌蛋白的生长抑制活性在与成熟果实中积累的水平相当的浓度下很强，并且在1 m葡萄糖（浆果中的生理己糖浓度）存在的情况下，这些活性可提高多达70%。浆果成熟过程中抗真菌蛋白和糖类的同时积累与果实成熟过程中发生的病原体抗性特征性发育相关。综上所述，这些蛋白质与糖类结合积累，似乎构成了一种新的、受发育调节的针对成熟果实中植物病原体的防御机制。
