Abstract
? 2022Tobacco mosaic virus (TMV) is known to infect a wide range of plants, resulting in reduced yield and productivity. Novel, effective, and plant-based pesticides are required to protect plants against TMV infection. To identify novel anti-TMV agents from natural sources, we systematically studied the roots of Cynanchum paniculatum and isolated six new seco-pregnane C21 steroidal glycosides, along with 14 known compounds. Their structures were elucidated by comprehensive spectroscopic data analysis. The anti-TMV activity of compounds were screened using the half-leaf method. Biological tests revealed that compounds 1, 2, 5, 9, 10, 15, and 16 displayed significant anti-TMV activities compared with the positive control ningnanmycin. In addition, reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis confirmed the antiviral activity of these compounds, as evident from reduced TMV coat protein (TMV-CP) gene replication and TMV-CP protein expression. These compounds downregulated the expression of NtHsp70–1 and NtHsp70–261, indicating that these steroidal glycosides possibly inhibit the TMV infection by suppressing the expression of NtHsp70–1 and NtHsp70–061 expression.
NSTL
Elsevier