Sugar-induced plant growth is dependent on brassinosteroids.
Sugars, the end products of photosynthesis, not only fuel growth and development of plants as carbon and energy sources, but also function as signaling molecules to modulate a range of important processes during plant growth and development. We recently found that sugar can promote hypocotyl elongation in Arabidopsis in darkness and this is largely dependent on brassinosteroids (BRs), a group of essential phytohormones involved in mediation of plant cell elongation. Sugars not only positively regulate the transcription of BZR1, the gene encoding the BR-activated transcription factor BRASSINAZOLE RESISTANT1 (BRZ1), but also stabilize the BZR1 protein. Based on these results, we proposed that BZR1 may act as a converging node for crosstalk between BR and sugar signaling in regulating plant growth in darkness. In this short communication, we present some new data showing that HEXOKINASE1 (HXK1), the first identified glucose (Glc) sensor in plants, was positively involved in Glc promotion of hypocotyl elongation in Arabidopsis in the dark. It appears that the function of HXK1 is dependent on the presence of BR, suggesting that BR may act downstream of HXK1 to positively regulate Glc-induced hypocotyl elongation in Arabidopsis in darkness.
a School of Life Sciences and State Key Laboratory of Agrobiotechnology; The Chinese University of Hong Kong ; Shatin , Hong Kong SAR , China.|b Key Laboratory of Cell Activities and Stress Adaptations; Ministry of Education; School of Life Sciences; Lanzhou University ; Lanzhou , China.
Yongqiang
Y
Zhang
a School of Life Sciences and State Key Laboratory of Agrobiotechnology; The Chinese University of Hong Kong ; Shatin , Hong Kong SAR , China.
Junxian
J
He
D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000378:metabolism; D060406:Brassinosteroids / Q000494:pharmacology*; D002241:Carbohydrates / Q000494:pharmacology*; D003624:Darkness; D060146:Ecotype; D006593:Hexokinase / Q000378:metabolism; D018546:Hypocotyl / Q000187:drug effects / Q000254:growth & development; D063245:Plant Development / Q000187:drug effects*; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development
D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002241:Carbohydrates; D006593:Hexokinase; C473630:ATHXK1 protein, Arabidopsis
BR; darkness; glucose HXK1; hypocotyl elongation; sugar