Open AccessLTP3 contributes to disease susceptibility in A rabidopsis by enhancing abscisic acid ( ABA ) biosynthesis
Author(s) -
Gao Shan,
Guo Wenya,
Feng Wen,
Liu Liang,
Song Xiaorui,
Chen Jian,
Hou Wei,
Zhu Hongxia,
Tang Saijun,
Hu Jian
Publication year - 2016
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1111/mpp.12290
Subject(s) - abscisic acid , pseudomonas syringae , biology , salicylic acid , arabidopsis , mutant , biosynthesis , gene , bacteria , plant disease resistance , microbiology and biotechnology , biochemistry , genetics
Summary Several plant lipid transfer proteins ( LTP s) act positively in plant disease resistance. Here, we show that LTP3 ( A t5g59320), a pathogen and abscisic acid ( ABA )‐induced gene, negatively regulates plant immunity in A rabidopsis . The overexpression of LTP3 ( LTP3 ‐OX ) led to an enhanced susceptibility to virulent bacteria and compromised resistance to avirulent bacteria. On infection of LTP3 ‐OX plants with P seudomonas syringae pv. tomato , genes involved in ABA biosynthesis, NCED3 and AAO3 , were highly induced, whereas salicylic acid ( SA )‐related genes, ICS1 and PR1 , were down‐regulated. Accordingly, in LTP3 ‐ OX plants, we observed increased ABA levels and decreased SA levels relative to the wild‐type. We also showed that the LTP3 overexpression‐mediated enhanced susceptibility was partially dependent on AAO3 . Interestingly, loss of function of LTP3 ( ltp3‐1 ) did not affect ABA pathways, but resulted in PR1 gene induction and elevated SA levels, suggesting that LTP3 can negatively regulate SA in an ABA ‐independent manner. However, a double mutant consisting of ltp3‐1 and silent LTP4 ( ltp3/ltp4 ) showed reduced susceptibility to P seudomonas and down‐regulation of ABA biosynthesis genes, suggesting that LTP3 acts in a redundant manner with its closest homologue LTP4 by modulating the ABA pathway. Taken together, our data show that LTP3 is a novel negative regulator of plant immunity which acts through the manipulation of the ABA–SA balance.