Bensulfuron-Methyl Treatment of Soil Affects the Infestation of Whitefly, Aphid, and Tobacco Mosaic Virus on Nicotiana 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 of Bemisia tabaci, Myzus persicae, and Tobacco mosaic virus (TMV) in Nicotiana tabacum. The soil was treated with BSM before the pest inoculation. The herbicide-treated tobaccos showed resistance to B. tabaci, but this resistance could not be detected until 15-day post-infestation when smaller number of adults B. tabaci appeared. In M. persicae assay, 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 as NtWIPK, NtPR1a, and NtPAL. NtPR1a and NtPAL were initially suppressed after virus-inoculation, while NtRDR1 and NtRDR6, 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.

Effect of some insecticides alone and in combination with salicylic acid against aphid, Aphis gossypii, and whitefly Bemisia tabaci on the cotton field

“…In addition, our results showed that the tested insecticides significantly increased the leaf phenolic content, which may be because any change in a plant that occurs following herbivory or environmental factors is an induced response (Ti and Zhang 2009). Exposure of tobacco plants Nicotiana tabacum to soil application with Bensulfuron-methyl (BSM) herbicide increased jasmonic acid (JA) and SA concentrations and increased plant resistance to whiteflies (B. tabaci) and aphids (M. persicae) with the activation of resistance genes (Li et al, 2016).…”

Effects of bensulfuron-methyl residue on photosynthesis and chlorophyll fluorescence in leaves of cucumber seedlings

“…The exposure of plants to herbicide residue induces many changes in morphological and physiological parameters. Herbicide residues are receiving increasing attention as they threaten crop yield and the safety of the environment, as well as human health[16]. A great deal of effort has been expended to solve these problems, such as detection of residues and biodegradation in soil[1–2,17].…”

History of the Emergence and Spatiotemporal Spread of Tobacco Mosaic Virus in China

“…Only recently Chinese researchers revealed that the plant immune response against TMV in tobacco strengthens due to the presence of residues of the herbicide Bensulfuron-methyl (BSM) in treated tobacco plants and soils. The latter then results in increased levels of the phytohormones, jasmonic acid (JA) and salicylic acid (SA); up-regulation of NtRDR1 and NtRDR6 genes key to fighting TMV and the expression of target genes (NtWIPK, NtPR1a, NtPAL) in the JA and SA signaling pathway [81].…”