Okon Odiong Unung, Houssam Eddine Said Bensedira, Takakazu Matsuura, Izumi C. Mori, Yuta Shimomura, Takashi Yaeno, Hidetaka Kaya, Kappei Kobayashi
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引用次数: 0
Abstract
In the inducible chlorosis model tobacco, i-hpHSP90C, the silencing of HSP90C activated both salicylic acid (SA)- and cell death-related gene expression and sporadic cell death, resulting in severe chlorosis. In this model plant, we found a transient SA accumulation to a significantly high level at 8 h after induction of HSP90C silencing and consistent upregulation of CBP60-type transcription factors and some SA biosynthetic genes. Exogenous treatment of the model plant with SA alone did not induce chlorosis. The introgression of a gene encoding SA-degrading enzyme, nahGA430V, into tobacco plants with functional N′ tobamovirus resistance gene partially compromised their resistance to tomato mosaic virus but without a clear reduction in SA levels. Expression of nahGA430V stochastically alleviated chlorosis and, subsequently, sporadic cell death upon induction of HSP90C silencing. We applied tenoxicam, a potent inhibitor of the NPR1-dependent SA signaling pathway in Arabidopsis, and found that it alleviated chlorosis in i-hpHSP90C, which accompanied a reduced expression of a CBP60-type transcription factor. However, the expression of PR1a, a well-characterized SA signal marker, was not suppressed by tenoxicam in the i-hpHSP90 plants with alleviated chlorosis. The findings collectively suggest that the plant immunity-related response, including SA production, could have a role in increasing the severity of chlorosis, although the underlying mechanisms remain to be elucidated.
期刊介绍:
The Journal of General Plant Pathology welcomes all manuscripts dealing with plant diseases or their control, including pathogen characterization, identification of pathogens, disease physiology and biochemistry, molecular biology, morphology and ultrastructure, genetics, disease transmission, ecology and epidemiology, chemical and biological control, disease assessment, and other topics relevant to plant pathological disorders.