The Resistance Responses of Potato Plants to Potato Virus Y Are Associated with an Increased Cellular Methionine Content and an Altered SAM:SAH Methylation Index

Abstract

Plant-virus interactions are frequently influenced by elevated temperature, which often increases susceptibility to a virus, a scenario described for potato cultivar Chicago infected with potato virus Y (PVY). In contrast, other potato cultivars such as Gala may have similar resistances to PVY at both normal (22 °C) and high (28 °C) temperatures. To elucidate the mechanisms of temperature-independent antivirus resistance in potato, we analysed responses of Gala plants to PVY at different temperatures using proteomic, transcriptional and metabolic approaches. Here we show that in Gala, PVY infection generally upregulates the accumulation of major enzymes associated with the methionine cycle (MTC) independently of temperature, but that temperature (22° C or 28° C) may finely regulate what classes accumulate. The different sets of MTC-related enzymes that are up-regulated at 22 °C or 28 °C likely account for the significantly increased accumulation of S-adenosyl methionine (SAM), a key component of MTC which acts as a universal methyl donor in methylation reactions. In contrast to this, we found that in cultivar Chicago, SAM levels were significantly reduced which correlated with the enhanced susceptibility to PVY at high temperature. Collectively, these data suggest that MTC and its major transmethylation function determines resistance or susceptibility to PVY.

Transcriptomic Reprogramming, Alternative Splicing and RNA Methylation in Potato (Solanum tuberosum L.) Plants in Response to Potato Virus Y Infection

“…Many of these processes may be regulated by transcription factors such as members of the MYB or WRKY families, which are regarded as key determinants for defence and development in plants and are affected by PVY infection and heat. Collectively, these observations are consistent with and confirm previously published data on transcriptomic and proteomic analyses of plant responses to virus infections and abiotic stresses [ 21 , 22 , 28 , 47 , 48 , 49 ].…”

“…In addition to methyltransferases, S-adenosylmethionine synthase 2 gene (SAMS2) (Soltu.DM.12G001940) were found in cluster 1. As was shown previously, enzymes associated with methionine cycle and trans-methylation play pivotal roles in plant–virus interactions since they determine resistance or susceptibility to viruses [ 20 , 21 , 22 ].…”

“…Interestingly, plant antiviral-resistance mechanisms may also be regulated via the functional interplay between viruses and the methionine cycle (MTC; [ 20 , 21 , 22 ]). We previously demonstrated that PVY infection generally upregulates the accumulation of major MTC enzymes in PVY-resistant potato cv Gala, leading to a significantly increased accumulation of S-adenosyl methionine (SAM), a key component of MTC which acts as a universal methyl donor in trans-methylation reactions.…”

Quantitative proteomic dataset of the moss Physcomitrium patens PSEP3 KO and OE mutant lines

“…LC-MS/MS analysis was conducted as described in our previous studies [15 , 16] . Peptides were separated on Acclaim PepMap 100 C18 (75 µm × 50 cm) (Thermo Fisher Scientific).…”

Quantitative proteomic dataset of the moss Physcomitrium patens SMG1 KO mutant line

“…LC-MS/MS analysis was conducted as described in our previous studies [ 10 , 11 ]. Peptides were separated on Acclaim PepMap 100 C18 (75 × 50 cm) (Thermo Fisher Scientific).…”