Induction of UDP-glucose:salicylic acid glucosyltransferase activity in tobacco mosaic virus-inoculated tobacco (Nicotiana tabacum) leaves
- Rutgers Univ., New Brunswick, NJ (United States)
Salicylic acid (SA) is a putative signal that activates plant resistance to pathogens. SA levels increase systemically following the hypersensitive response produced by tobacco masaic virus (TMV) inoculation of tobacco (Nicotiana tabacum L. cv Xanthi-nc) leaves. The SA increase in the inoculated leaf coincided with the appearance of a [beta]-glucosidase-hydrolyzable SA conjugate identified as [beta]-O-D-glucosylsalicylic acid (GSA). SA and GSA accumulation in the TMV-inoculated leaf paralleled the increase in the activity of a UDP-glucose:salicylic acid 3-O-glucosyltransferase (EC 2.4.1.35) ([beta]-GTase) capable of converting SA to GSA. Healthy tissues had constitutive [beta]-GTase activity of 0.076 milliunits g[sup [minus]1] fresh weight. This activity started to increase 48 h after TMV inoculation, reaching its maximum (6.7-fold induction over the basal levels) 72 h after TMV inoculation. No significant GSA or elevated [beta]-GTase activity could be detected in the healthy leaf immediately above the TMV-inoculated leaf. The effect of TMV inoculation on the [beta]-GTase and GSA accumulation could be duplicated by infiltrating tobacco leaf discs with SA at the levels naturally produced in TMV-inoculated leaves (2.7--27.0 [mu]g g[sup [minus]1] fresh weight). Pretreatment of leaf discs with the protein synthesis inhibitor cycloheximide inhibited the induction of [beta]GTase by SA and prevented the formation of GSA. Of 12 analogs of SA tested, only 2,6-dihydroxybenzoic acid induced [beta]-GTase activity. 21 refs., 5 figs.
- DOE Contract Number:
- FG05-91ER20049
- OSTI ID:
- 6200018
- Journal Information:
- Plant Physiology; (United States), Vol. 101:4; ISSN 0032-0889
- Country of Publication:
- United States
- Language:
- English
Similar Records
Pathway of salicylic acid biosynthesis in healthy and virus-inoculated tobacco
Endogenous salicylic acid levels correlate with accumulation of pathogenesis-related proteins and virus resistance in tobacco
Related Subjects
PLANTS
PATHOGENS
RESPONSE MODIFYING FACTORS
CYCLOHEXIMIDE
ENZYMES
GLUCOSE
GLUCOSIDASE
NICOTIANA
SALICYLIC ACID
TOBACCO
TOBACCO MOSAIC VIRUS
ALDEHYDES
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
CARBOHYDRATES
CARBOXYLIC ACIDS
DRUGS
FUNGICIDES
GLYCOSYL HYDROLASES
HEXOSES
HYDROLASES
HYDROXY ACIDS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MICROORGANISMS
MONOSACCHARIDES
O-GLYCOSYL HYDROLASES
ORGANIC ACIDS
ORGANIC COMPOUNDS
PARASITES
PESTICIDES
PROTEINS
SACCHARIDES
VIRUSES
550200* - Biochemistry