Metabolic changes sustain the plant life in low-sulfur environments

•Multiple mechanisms to up-regulate sulfate uptake in low sulfur environment.•Sulfate transporters act as sulfate receptors.•Contribution of SLIM1 transcription factor to controlling metabolic flow of sulfur in response to sulfur deficiency.•Sulfur deficiency-induced repression of aliphatic glucosinolates biosynthesis.•Catabolism of organic sulfur compounds accelerated under sulfur deficiency.

Plants assimilate inorganic sulfate into various organic sulfur (S) compounds, which contributes to the global sulfur cycle in the environment as well as the nutritional supply of this essential element to animals. Plants, to sustain their lives, adapt the flow of their S metabolism to respond to external S status by activating S assimilation and catabolism of stored S compounds, and by repressing the synthesis of secondary S metabolites like glucosinolates. The molecular mechanism of this response has been gradually revealed, including the discovery of several regulatory proteins and enzymes involved in S deficiency responses. Recent progress in this research area and the remaining issues are reviewed here.