Endogenous salicylic acid levels correlate with accumulation of pathogenesis-related proteins and virus resistance in tobacco

Journal Article · Thu Jul 01 00:00:00 EDT 1993 · Phytopathology (An International Journal); (United States)

DOI:https://doi.org/10.1094/Phyto-83-702· OSTI ID:5974414

Yalpani, N; Shulaev, V; Raskin, I ^[1]

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1. Rutgers Univ., New Brunswick, NJ (United States)

Salicylic acid (SA) is hypothesized to be an endogenous regulator of local and systemic disease resistance and an inducer of pathogenesis-related (PR) proteins among plants. High levels of PR proteins have been observed in an uninoculated amphidiploid hybrid of Nicotiana glutinosa [times] N. debneyi, which is highly resistant to tobacco mosaic virus (TMV). Fluoresence, UV, and mass spectral analysis established that the levels of SA in healthy N. glutinosa [times] N. debneyi leaves were 30 times greater than in N. tabacum [open quotes]Xanthi-nc[close quotes] tobacco, which does not constitutively express PR proteins and is less resistant to TMV. Upon TMV-inoculation SA levels increased at least 70-fold leaves of Xanthi-nc but role only slightly in the hybrid. Phloem exudates of N. glutinosa [times] N. debneyi contained at least 500 times more SA than those of Xanthi-nc. SA treatment caused the appearance of PR-1 protein in Xanthi-nc but did not affect constitutively high levels of PR-1 protein in N. glutinosa [times] N. debneyi. In contrast to Xanthi-nc tobacco, TMV-inoculated N. glutinosa [times] N. debneyi kept at 32 C accumulated more than 0.5 [mu]g SA/g fresh weight, maintained high levels of PR proteins, and developed a hypersensitive response to TMV. PR proteins have previously been shown to accumulate in the lower leaves of healthy, flowering Xanthi-nc tobacco, which exhibited increased resistance to TMV. These developmentally induced increases in resistance and PR-1 proteins positively correlated with tissue levels of SA. These results affirm the regulatory role of SA in disease resistance and PR protein production. 31 refs., 9 figs., 1 tab.

• OSTI ID: 5974414
• Journal Information: Phytopathology (An International Journal); (United States), Vol. 83:7; ISSN 0031-949X
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
NICOTIANA
DISEASE RESISTANCE
SALICYLIC ACID
ECOLOGICAL CONCENTRATION
LEAVES
LEVELS
PATHOGENESIS
PLANTS
PROTEINS
TOBACCO
TOBACCO MOSAIC VIRUS
CARBOXYLIC ACIDS
HYDROXY ACIDS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PARASITES
VIRUSES
550200* - Biochemistry