Role of two cysteine proteinases in the susceptible response of Nicotiana benthamiana to Colletotrichum destructivum and the hypersensitive response to Pseudomonas syringae pv. tomato

• Published in: Plant science (Limerick) Vol. 170; no. 5; pp. 1001 - 1009
• Main Authors: Hao, L., Hsiang, T., Goodwin, P.H.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-05-2006; Elsevier Science
• Subjects: Anthracnose; apoptosis; Bacterial plant pathogens; Biological and medical sciences; Colletotrichum destructivum; disease resistance; Fundamental and applied biological sciences. Psychology; gene amplification; gene silencing; hypersensitive response; Lycopersicon esculentum; molecular cloning; Nicotiana benthamiana; Papain; Pathology. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; Plant disease; plant pathogenic bacteria; plant pathogenic fungi; plant response; Pseudomonas syringae; Pseudomonas syringae pv. tomato; sequence analysis; Tobacco; Anthracnose; Papain; Tobacco; Plant disease; Cysteine; Growth; Cysteine endopeptidases; Fungi; Gene; Dicotyledones; Angiospermae; Lycopersicon esculentum; Fungi Imperfecti; Solanaceae; Thallophyta; Enzyme; Hypersensitivity; Plant leaf; Colletotrichum; Peptidases; Gene silencing; Complementary DNA; Hydrolases; Spermatophyta; Apoptosis
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2006.01.011

Two cysteine proteinase genes of the papain family,
NbCYP1 and
NbCYP2, were amplified from cDNA of
Nicotiana benthamiana leaves infected with the hemibiotrophic fungus
Colletotrichum destructivum. Both genes showed peak expression corresponding with the switch from biotrophic to necrotrophic growth by
C. destructivum at 72
h post-inoculation (HPI). For
N.
benthamiana inoculated with the incompatible bacterium,
Pseudomonas syringae pv.
tomato, expression of
NbCYP1 significantly decreased at 12
HPI, whereas
NbCYP2 expression increased at 3
HPI. Expression of both genes then returned to near pre-inoculation levels and remained constant as necrosis later appeared due to a non-host hypersensitive response (HR). Virus-induced gene silencing of
NbCYP1 and
NbCYP2 resulted in increased susceptibility of
N. benthamiana to
C. destructivum but did not affect the HR necrosis or population levels of
P. syringae pv.
tomato. These two cysteine proteinase genes do not appear to be involved in the programmed cell death of the HR resistance to
P. syringae pv.
tomato, but they are involved in limiting the host's susceptibility to
C. destructivum.