Identification of MaWRKY40 and MaDLO1 as Effective Marker Genes for Tracking the Salicylic Acid-Mediated Immune Response in Bananas
Journal
Phytopathology®
Journal Volume
111
Journal Issue
10
Start Page
1800
End Page
1810
ISSN
0031-949X
1943-7684
Date Issued
2021-10
Author(s)
Bo-Han Hou
Shu-Ming Tsao
Ho-Ming Chen
An-Po Cheng
Elena Gamboa Chen
Wei-Yi Chou
Chih-Ping Chao
Chyi-Chuann Chen
Ming-Chi Lee
Iqra Ashraf
Hsin-Hung Yeh
Abstract
Bananas are among the world’s most important cash and staple crops but are threatened by various devastating pathogens. The phytohormone salicylic acid (SA) plays a key role in the regulation of plant immune response. Tracking the expression of SA-responsive marker genes under pathogen infection is important in pathogenesis elucidation. However, the common SA-responsive marker genes are not consistently induced in different banana cultivars or different organs. Here, we conducted transcriptome analysis for SA response of a banana cultivar, ‘Pei-Chiao’ (Cavendish, AAA genome), and identified three genes, MaWRKY40, MaWRKY70, and Downy Mildew Resistant 6 (DMR6)-Like Oxygenase 1 (MaDLO1) that are robustly induced upon SA treatment in both the leaves and roots. Consistent induction of these three genes by SA treatment was also detected in both the leaves and roots of bananas belonging to different genome types such as ‘Tai-Chiao No. 7’ (Cavendish, AAA genome), ‘Pisang Awak’ (ABB genome), and ‘Lady Finger’ (AA genome). Furthermore, the biotrophic pathogen cucumber mosaic virus elicited the expression of MaWRKY40 and MaDLO1 in infected leaves of susceptible cultivars. The hemibiotrophic fungal pathogen Fusarium oxysporum f. sp. cubense tropical race 4 (TR4) also consistently induced the expression of MaWRKY40 and MaDLO1 in the infected roots of the F. oxysporum f. sp. cubense TR4-resistant cultivar. These results indicate that MaWRKY40 and MaDLO1 can be used as reliable SA-responsive marker genes for the study of plant immunity in banana. Revealing SA-responsive marker genes provides a stepping stone for further studies in banana resistance to pathogens.
Subjects
Banana
Cucumber mosaic virus
Fusarium oxysporum f. sp. cubense tropical race 4
Marker gene
Plant immune response
Salicylic acid
Publisher
Scientific Societies
Type
journal article