Effect of Temperature on the Expression of Necrosis in Soybean Infected with Soybean mosaic virus
- C. Zhenga,
- P. Chen *a and
- R. Gergerichb
Soybean mosaic virus (SMV) causes mosaic symptoms in susceptible soybean [Glycine max (L.) Merr.] cultivars and stem-tip necrosis (STN) in some soybean cultivars carrying resistance genes. The objective of this study was to examine the effect of different temperature regimes on the expression of SMV-induced STN. Three soybean isolines, ‘Essex’ (rsv, mosaic to SMV strains G1 and G7), V94-3971 (Rsv1, resistant to G1 and necrotic to G7), and V262 (Rsv1-n, necrotic to G1 and mosaic to G7), were inoculated with G1 and G7 and maintained in growth chambers with a 12-h photoperiod and constant temperatures of 10, 15, 20, 25, 30, 32, 33, and 35°C. The STN in V262 induced by G1 and in V94-3971 by G7 developed at 10, 15, 20, 25, and 30°C, on 44, 41, 14, 8, 8 days after inoculation (DAI), respectively. No STN reaction was induced by either strain at 35°C. Further study demonstrated that STN was induced 7 DAI at 32°C in V262 by G1 and in V94-3971 by G7, but mosaic symptoms developed in both genotypes at 33°C. However, STN was induced in V262 7 DAI by G1 and in V94-3971 14 DAI by G7 at an alternate temperature of 33°C day/20°C night. Stem-tip necrosis was also observed in V262 8 DAI by G1, but not in V94-3971 by G7 at an alternate temperature 35°C day/20°C night. Essex exhibited mosaic symptoms when infected with G1 and G7 at all temperatures tested, and virus was detected by enzyme-linked immunosorbent assay (ELISA). Stem-tip necrosis is a SMV strain-specific, thermosensitive response associated with SMV resistance genes.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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