High serine:glyoxylate aminotransferase activity lowers leaf daytime serine levels, inducing the phosphoserine pathway in Arabidopsis.

ABSTRACT: Serine:glyoxylate aminotransferase (SGAT) converts glyoxylate and serine to glycine and hydroxypyruvate during photorespiration. Besides this, SGAT operates with several other substrates including asparagine. The impact of this enzymatic promiscuity on plant metabolism, particularly photorespiration and serine biosynthesis, is poorly understood. We found that elevated SGAT activity causes surprisingly clear changes in metabolism and interferes with photosynthetic CO2 uptake and biomass accumulation of Arabidopsis. The faster serine turnover during photorespiration progressively lowers day-time leaf serine contents and in turn induces the phosphoserine pathway. Transcriptional upregulation of this additional route of serine biosynthesis occurs already during the day but particularly at nigh

SUBMITTER: Modde K 

PROVIDER: S-EPMC5441925 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature