Open AccessContribution of the drought tolerance‐related Stress‐responsive NAC 1 transcription factor to resistance of barley to R amularia leaf spot
Author(s) -
McGrann Graham R. D.,
Steed Andrew,
Burt Christopher,
Goddard Rachel,
Lachaux Clea,
Bansal Anuradha,
Corbitt Margaret,
Gorniak Kalina,
Nicholson Paul,
Brown James K. M.
Publication year - 2015
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.12173
Subject(s) - biology , blumeria graminis , powdery mildew , abiotic component , leaf spot , abiotic stress , senescence , plant disease resistance , botany , transcription factor , microbiology and biotechnology , gene , genetics , paleontology
Summary NAC proteins are plant transcription factors that are involved in tolerance to abiotic and biotic stresses, as well as in many developmental processes. Stress‐responsive NAC 1 ( SNAC1 ) transcription factor is involved in drought tolerance in barley and rice, but has not been shown previously to have a role in disease resistance. Transgenic over‐expression of HvSNAC1 in barley cv. Golden Promise reduced the severity of R amularia leaf spot ( RLS ), caused by the fungus R amularia collo ‐ cygni , but had no effect on disease symptoms caused by F usarium culmorum , O culimacula yallundae (eyespot), B lumeria graminis f. sp. hordei (powdery mildew) or M agnaporthe oryzae (blast). The HvSNAC1 transcript was weakly induced in the RLS ‐susceptible cv. Golden Promise during the latter stages of R. collo ‐ cygni symptom development when infected leaves were senescing. Potential mechanisms controlling HvSNAC1 ‐mediated resistance to RLS were investigated. Gene expression analysis revealed no difference in the constitutive levels of antioxidant transcripts in either of the over‐expression lines compared with cv. Golden Promise, nor was any difference in stomatal conductance or sensitivity to reactive oxygen species‐induced cell death observed. Over‐expression of HvSNAC1 delayed dark‐induced leaf senescence. It is proposed that mechanisms controlled by HvSNAC1 that are involved in tolerance to abiotic stress and that inhibit senescence also confer resistance to R. collo ‐ cygni and suppress RLS symptoms. This provides further evidence for an association between abiotic stress and senescence in barley and the development of RLS .