ABSTRACT
Sucrose non-fermenting-1-related protein kinase 1 (SnRK1) has been located at the heart of the control of metabolism and development in plants. The active SnRK1 form is usually a heterotrimeric complex. Subcellular localization and specific target of the SnRK1 kinase are regulated by specific beta subunits. In Arabidopsis, there are at least seven genes encoding beta subunits, of which the regulatory functions are not yet clear. Here, we tried to study the function of one beta subunit, AKINbeta1. It showed that AKINbeta1 expression was dramatically induced by ammonia nitrate but not potassium nitrate, and the investigation of AKINbeta1 transgenic Arabidopsis and T-DNA insertion lines showed that AKINbeta1 negatively regulated the activity of nitrate ruductase and was positively involved in sugar repression in early seedling development. Meanwhile AKINbeta1 expression was reduced upon sugar treatment (including mannitol) and did not affect the activity of sucrose phosphate synthase. The results indicate that AKINbeta1 is involved in the regulation of nitrogen metabolism and sugar signaling.
Subject(s)
Arabidopsis Proteins/physiology , Arabidopsis/metabolism , Carbohydrates/physiology , Carrier Proteins/physiology , Nitrogen/metabolism , Arabidopsis/drug effects , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Carbohydrates/pharmacology , Carrier Proteins/genetics , Carrier Proteins/metabolism , DNA, Bacterial/genetics , Gene Expression Regulation, Plant/drug effects , Glucosyltransferases/metabolism , Nitrate Reductase/metabolism , Nitrates/pharmacology , Potassium Compounds/pharmacology , Signal Transduction/drug effects , Signal Transduction/genetics , Sucrose/pharmacologyABSTRACT
CAL (CAULIFLOWER) gene and AP1 (APETALA1) gene, which both belong to MADS-box transcription factors, are involved in the development of flower apical meristem. In A rabidopsis thaliana, loss of CAL and AP1 function at the same time leads to floweral meristems proliferation indeterminately, and the plants display the cauliflower phenotype. But in cauliflower (Brasscia oleracea L. var. botrytis), the BobCAL single mutant can display the cauliflower phenotype, it is appear that CAL and AP1 homolog have different function in both plants. To study the function of homozygous CAL , AP1 protein in Brassica Species, especially their regulation function in the formation of cauliflower, we took advantage of yeast-two-hybrid method to screen interaction factors of BoCAL. We got four kinds of proteins which are separately involve in phosphorylation and dephosphorylation of proteins, proteins modifying, proteins binding-site and so on. They separately have close relationship with translation, regulation pathways and signal transferring pathways and they provide clues for the study of function of BoCAL. Additionally, we checked up the relationship between some interacting factors of BoCAL and BoAP1, some known MADS-box translation factors and BoCAL and BoAP1. The results showed that BoCAL specifically interact with SnRKbeta2. BoCAL, BoAP1 both interact with SVP, similar as the homolog in Arabidopsis. While the interaction between BoCAL, BoAP1 with FLM, SOC1 and AGL24. The data here indicate the function of homozygous BoCAL and BoAP1 differ from that in Arabidopsis thaliana.