S-methylmethionine alters gene expression of candidate genes in Maize dwarf mosaic virus infected and drought stressed maize plants

Abstract

In the present work we investigated the potential beneficial effects of the exogenous application of S-methylmethionine (SMM) that plays an important role in the plants’ sulphur metabolism and contributes to the production of certain defence compounds. The possible beneficial effects were challenged against Maize dwarf mosaic virus infection and drought stress. We studied the expression changes of GF14-6 and SAMS during viral infection and DREB2A and DBP2 during drought stress. The product of GF14-6 recognise the viral coat protein and contributes to RNA-silencing, while the product of SAMS plays a central role in the plant sulphur metabolism and contributes to the production of several defence compounds. The products of DREB2A and DBP2 contribute to better plant defence against drought stress and increase the efficiency of water uptake. According to our results, SMM pretreatment has a considerable change on the investigated genes’ expression. It significantly decreases the gene expression of GF14-6, while infection results in a higher expression level. On the other hand, a more prolonged and long lasting increase is measured in SAMS expression as a result to SMM pretreatment followed by infection. SMM lessens the gene expression of DREB2A, while no changes were observed in DBP2 compared to drought stressed plants.