Cotton WRKY1 Mediates the Plant Defense-to-Development Transition during Infection of Cotton byVerticillium dahliaeby ActivatingJASMONATE ZIM-DOMAIN1Expression    

Abstract

Plants have evolved an elaborate signaling network to ensure an appropriate level of immune response to meet the differing demands of developmental processes. Previous research has demonstrated that DELLA proteins physically interact with JASMONATE ZIM-DOMAIN1 (JAZ1) and dynamically regulate the interaction of the gibberellin (GA) and jasmonate (JA) signaling pathways. However, whether and how the JAZ1-DELLA regulatory node is regulated at the transcriptional level in plants under normal growth conditions or during pathogen infection is not known. Here, we demonstrate multiple functions of cotton (Gossypium barbadense) GbWRKY1 in the plant defense response and during development. Although GbWRKY1 expression is induced rapidly by methyl jasmonate and infection by Verticillium dahliae, our results show that GbWRKY1 is a negative regulator of the JA-mediated defense response and plant resistance to the pathogens Botrytis cinerea and V. dahliae. Under normal growth conditions, GbWRKY1-overexpressing lines displayed GA-associated phenotypes, including organ elongation and early flowering, coupled with the down-regulation of the putative targets of DELLA. We show that the GA-related phenotypes of GbWRKY1-overexpressing plants depend on the constitutive expression of Gossypium hirsutum GhJAZ1. We also show that GhJAZ1 can be transactivated by GbWRKY1 through TGAC core sequences, and the adjacent sequences of this binding site are essential for binding specificity and affinity to GbWRKY1, as revealed by dual-luciferase reporter assays and electrophoretic mobility shift assays. In summary, our data suggest that GbWRKY1 is a critical regulator mediating the plant defense-to-development transition during V. dahliae infection by activating JAZ1 expression.

WRKY1 acts as a key component improving resistance against Alternaria solani in wild tomato, Solanum arcanum Peralta

“…As T 0 W1RNAi silencing transgenic plants had poor seed setting, we were unable to get viable T 1 generation. As previously shown in cotton, this might be due to dual role of WRKY1 in plant growth and development as well as in defence (Li et al ., ), and thus, WRKY1 silencing might have affected seed setting resulting into loss of viable T 1 generation. Two independent W1OE lines (W1OE‐1 and W1OE‐8) exhibited significant elevation of SlWRKY1 transcripts (15‐ and 21‐fold, respectively) compared to wild‐type (WT) plants in the absence of pathogen (Figure S10a).…”

Long noncoding RNAs involve in resistance to Verticillium dahliae, a fungal disease in cotton

“…VW is caused by soil‐borne fungus Verticillium dahliae , which worldwide invades more than 400 plant species hosts (Li et al ., ; Zhang et al ., ). This disease will lead to chlorosis and wilt of leaves or defoliation, the browning of vascular and even death ultimately (Li et al ., ; Xu et al ., ). It has been the major challenge for cotton and deserves enormous researches to control efficiently.…”

The Thioredoxin GbNRX1 Plays a Crucial Role in Homeostasis of Apoplastic Reactive Oxygen Species in Response to Verticillium dahliae Infection in Cotton

“…Global analyses have demonstrated that several signaling pathways, including those mediated by salicylic acid, ethylene, jasmonic acid, and brassinosteroids, activate distinct processes involved in V. dahliae defense (Bari and Jones, 2009;Grant and Jones, 2009;Gao et al, 2013a). Accumulating evidence indicates that many V. dahliae-responsive genes, such as GbWARKY1, GhSSN, GbERF, GhMLP28, GhNDR1, GhMKK2, and GhBAK1 (Qin et al, 2004;Gao et al, 2011Gao et al, , 2013bLi et al, 2014a;Sun et al, 2014;Yang et al, 2015), play crucial roles in defense against Verticillium wilt. In addition, the biosynthesis of terpenoids, lignin, and gossypol also makes important contributions to V. dahliae resistance in cotton (Tan et al, 2000;Luo et al, 2001;Xu et al, 2011;Gao et al, 2013a).…”