Guan Xin, Buchholz Günther, Nick Peter
Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76128 Karlsruhe, Germany; College of Horticulture and Landscape Architecture, Southwest University, 400716 Chongqing, China.
RLP AgroScience/AlPlanta - Institute for Plant Research, Breitenweg 71, D-67435 Neustadt an der Weinstraße, Germany.
J Plant Physiol. 2014 Aug 15;171(13):1164-73. doi: 10.1016/j.jplph.2014.03.019. Epub 2014 May 4.
Resistance to abiotic and biotic stress is a central topic for sustainable agriculture, especially in grapevine, one of the field crops with the highest economic output per acreage. As early cellular factors for plant defense, actin microfilaments (AF) are of high relevance. We therefore generated a transgenic actin marker line for grapevine by expressing a fusion protein between green fluorescent protein and the second actin-binding domain of Arabidopsis (Arabidopsis thaliana) fimbrin, AtFIM1. Based on this first cytoskeletal-marker line in grapevine, the response of AFs to phytopathogenic microorganisms could be followed in vivo. Upon inoculation with fluorescently labeled strains of phytopathogenic bacteria, actin responses were confined to the guard cells. In contrast, upon contact with zoospores of Plasmopara viticola, not only the guard cells, but also epidermal pavement cells, where no zoospores had attached responded with the formation of a perinuclear actin basket. Our data support the hypothesis that guard cells act as pacemakers of defense, dominating the responses of the remaining epidermal cells.
对非生物和生物胁迫的抗性是可持续农业的核心课题，在葡萄中尤为如此，葡萄是单位种植面积经济产量最高的大田作物之一。作为植物防御的早期细胞因子，肌动蛋白微丝（AF）具有高度相关性。因此，我们通过表达绿色荧光蛋白与拟南芥丝状肌动蛋白结合蛋白AtFIM1的第二个肌动蛋白结合结构域之间的融合蛋白，构建了一个葡萄转基因肌动蛋白标记系。基于葡萄中的首个细胞骨架标记系，可以在体内追踪AF对植物病原微生物的反应。接种荧光标记的植物病原细菌菌株后，肌动蛋白反应局限于保卫细胞。相比之下，与葡萄霜霉病菌游动孢子接触后，不仅保卫细胞，而且没有游动孢子附着的表皮铺路细胞也会形成核周肌动蛋白篮。我们的数据支持以下假设：保卫细胞作为防御的起搏器，主导其余表皮细胞的反应。
