Functional analysis of cytoskeletal signalling in the defence response of grapevine

This study followed the responses of actin filaments and microtubules to flg22 and HrpZ in vivo by spinning-disc confocal microscopy in Green fluorescent protein (GFP)-tagged marker lines of tobacco BY-2. Cytoskeletal disruption is proposed as an early event that discriminates HrpZ-triggered ETI-like defence from flg22-triggered PTI. We have generated a transgenic grapevine plant line of Vitis vinifera 'Chardonnay' expressing a fusion protein between GFP and the second actin-binding domain of Arabidopsis (Arabidopsis thaliana) fimbrin, AtFIM1 (pK7WGF2-FABD2), and a suspension cell line of the American Rock Grape Vitis rupestris expressing Arabidopsis beta-Tubulin-6 N-terminally fused to GFP (pCambia1300(CAA)n 2XT-gfp-Tub6). Our work succeeded to integrate life-cell imaging of the cytoskeleton into the model plant grapevine and thus to investigate the function of actin filaments and microtubules in context that is highly relevant for application in agriculture.