title: Bensulfuron-Methyl Treatment of Soil Affects the Infestation of Whitefly, Aphid, andTobacco Mosaic VirusonNicotiana tabacum.
abstract: Bensulfuron-methyl (BSM) is widely used in paddy soil for weed control. BSM residue in the soil has been known to inhibit the growth of sensitive crop plants. However, it is unknown whether BSM residue can affect the agrosystem in general. In this study, we have found significant effects of BSM on the infestation ofBemisia tabaci,Myzus persicae, andTobacco mosaic virus(TMV) inNicotiana tabacum. The soil was treated with BSM before the pest inoculation. The herbicide-treated tobaccos showed resistance toB. tabaci, but this resistance could not be detected until 15-day post-infestation when smaller number of adultsB. tabaciappeared. InM. persicaeassay, the longevity of all development stages of insects, and the fecundity of insects were not significantly affected when feeding on BSM-treated plants. In TMV assay, the BSM treatment also reduced virus-induced lesions in early infection time. However, the titer of TMV in BSM treated plants increased greatly over time and was over 40-fold higher than the mock-infected control plants after 20 days. Further studies showed that BSM treatment increased both jasmonic acid (JA) and salicylic acid (SA) levels in tobacco, as well as the expression of target genes in the JA and SA signaling pathways, such asNtWIPK,NtPR1a, andNtPAL. NtPR1aandNtPALwere initially suppressed after virus-inoculation, whileNtRDR1andNtRDR6, which play a key role in fighting virus infection, only showed up- or were down-regulated 20 days post virus-inoculation. Taken together, our results suggested that BSM residue in the soil may affect the metabolism of important phytohormones such as JA and SA in sensitive plants and consequently affect the plant immune response against infections such as whitefly, aphids, and viruses.
authors.affiliation: Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Renyi
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Saif Ul
authors.initials: SU
authors.lastname: Islam
authors.affiliation: Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry University Fuzhou, China.
authors.forename: Zujian
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Key Laboratory of Plant Virology of Fujian Province, Institute of Plant Virology, Fujian Agriculture and Forestry UniversityFuzhou, China; Key laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry UniversityFuzhou, China.
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Ye
keywords: Bemisia tabaci; Myzus persicae; Tobacco mosaic virus; herbicide; jasmonic acid; salicylic acid