AUTHOR=Dou Mengru , Li Yuhang , Hao Yu , Zhang Kangzhuang , Yin Xiao , Feng Zinuo , Xu Xi , Zhang Qi , Bao Wenwu , Chen Xi , Liu Guotian , Wang Yuejin , Tian Ling , Xu Yan 

TITLE=Histological and transcriptomic insights into the interaction between grapevine and Colletotrichum viniferum

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1446288

DOI=10.3389/fpls.2024.1446288

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Grape is of high economic value. <italic>Colletotrichum viniferum</italic>, a pathogen causing grape ripe rot and leaf spot, threatens grape production and quality.</p></sec><sec><title>Methods</title><p>This study investigates the interplay between <italic>C. viniferum</italic> by Cytological study and transcriptome sequencing.</p></sec><sec><title>Results</title><p>Different grapevine germplasms, <italic>V. vinifera</italic> cv. Thompson Seedless (TS), <italic>V. labrusca</italic> accession Beaumont (B) and <italic>V. piasezkii</italic> Liuba-8 (LB-8) were classified as highly sensitive, moderate resistant and resistant to <italic>C. viniferum</italic>, respectively. Cytological study analysis reveals distinct differences between susceptible and resistant grapes post-inoculation, including faster pathogen development, longer germination tubes, normal appressoria of <italic>C. viniferum</italic> and absence of white secretions in the susceptible host grapevine. To understand the pathogenic mechanisms of <italic>C. viniferum</italic>, transcriptome sequencing was performed on the susceptible grapevine “TS” identifying 236 differentially expressed <italic>C. viniferum</italic> genes. These included 56 effectors, 36 carbohydrate genes, 5 P450 genes, and 10 genes involved in secondary metabolism. Fungal effectors are known as pivotal pathogenic factors that modulate plant immunity and affect disease development. <italic>Agrobacterium</italic>-mediated transient transformation in <italic>Nicotiana benthamiana</italic> screened 10 effectors (CvA13877, CvA01508, CvA05621, CvA00229, CvA07043, CvA05569, CvA12648, CvA02698, CvA14071 and CvA10999) that inhibited INF1 (infestans 1, <italic>P. infestans</italic> PAMP elicitor) induced cell death and 2 effectors (CvA02641 and CvA11478) that induced cell death. Additionally, transcriptome analysis of “TS” in response to <italic>C. viniferum</italic> identified differentially expressed grape genes related to plant hormone signaling (<italic>TGA</italic>, <italic>PR1</italic>, <italic>ETR</italic>, and <italic>ERF1/2</italic>), resveratrol biosynthesis genes (<italic>STS</italic>), phenylpropanoid biosynthesis genes (<italic>PAL</italic> and <italic>COMT</italic>), photosynthetic antenna proteins (<italic>Lhca</italic> and <italic>Lhcb</italic>), transcription factors (<italic>WRKY</italic>, <italic>NAC</italic>, <italic>MYB</italic>, <italic>ERF</italic>, <italic>GATA</italic>, <italic>bHLH</italic> and <italic>SBP</italic>), ROS (reactive oxygen species) clearance genes (<italic>CAT</italic>, <italic>GSH</italic>, <italic>POD</italic> and <italic>SOD</italic>), and disease-related genes (<italic>LRR</italic>, <italic>RPS2</italic> and <italic>GST</italic>).</p></sec><sec><title>Discussion</title><p>This study highlights the potential functional diversity of <italic>C. viniferum</italic> effectors. Our findings lay a foundation for further research of infection mechanisms in <italic>Colletotrichum</italic> and identification of disease response targets in grape.</p></sec>