Extensive changes in plant transcriptome and metabolome have been observed by numerous research groups after transferring plants from optimal conditions to sulfur （S） deficiency. Despite intensive studies and recent...Extensive changes in plant transcriptome and metabolome have been observed by numerous research groups after transferring plants from optimal conditions to sulfur （S） deficiency. Despite intensive studies and recent important achievements, like identification of SLIM1/EIL3 as a major transcriptional regulator of the response to S-deficiency, many questions concerning other elements of the regulatory network remain unanswered. Investigations of genes with expres- sion regulated by S-deficiency stress encoding proteins of unknown function might help to clarify these problems. This study is focused on the UP9C gene and the UP9-1ike family in tobacco. Homologs of these genes exist in other plant species, including a family of four genes of unknown function in Arabidopsis thaliana （LSUI-4）, of which two were reported as strongly induced by S-deficit and to a lesser extent by salt stress and nitrate limitation. Conservation of the predicted structural features, such as coiled coil region or nuclear localization signal, suggests that these proteins might have ira- portant functions possibly mediated by interactions with other proteins. Analysis of transgenic tobacco plants with si- lenced expression of UP9-1ike genes strongly argues for their significant role in regulation of plant response to S-deficit. Although our study shows that the UP9-1ike proteins are important components of such response and they might be also required during other stresses, their molecular functions remain a mystery.展开更多
文摘Extensive changes in plant transcriptome and metabolome have been observed by numerous research groups after transferring plants from optimal conditions to sulfur （S） deficiency. Despite intensive studies and recent important achievements, like identification of SLIM1/EIL3 as a major transcriptional regulator of the response to S-deficiency, many questions concerning other elements of the regulatory network remain unanswered. Investigations of genes with expres- sion regulated by S-deficiency stress encoding proteins of unknown function might help to clarify these problems. This study is focused on the UP9C gene and the UP9-1ike family in tobacco. Homologs of these genes exist in other plant species, including a family of four genes of unknown function in Arabidopsis thaliana （LSUI-4）, of which two were reported as strongly induced by S-deficit and to a lesser extent by salt stress and nitrate limitation. Conservation of the predicted structural features, such as coiled coil region or nuclear localization signal, suggests that these proteins might have ira- portant functions possibly mediated by interactions with other proteins. Analysis of transgenic tobacco plants with si- lenced expression of UP9-1ike genes strongly argues for their significant role in regulation of plant response to S-deficit. Although our study shows that the UP9-1ike proteins are important components of such response and they might be also required during other stresses, their molecular functions remain a mystery.
