The DOF-Domain Transcription Factor ZmDOF36 Positively Regulates Starch Synthesis in Transgenic Maize

Abstract

Starch synthesis is a complex process that influences crop yield and grain quality in maize. Many key enzymes have been identified in starch biosynthesis; however, the regulatory mechanisms have not been fully elucidated. In this study, we identified a DOF family gene, ZmDOF36 , through transcriptome sequencing analysis. Real-time PCR indicated that ZmDOF36 was highly expressed in maize endosperm, with lower expression in leaves and tassels. ZmDOF36 is a typical DOF transcription factor (TF) that is localized to the nucleus and possesses transcriptional activation activity, and its transactivation domain is located in the C-terminus (amino acids 227–351). Overexpression of ZmDOF36 can increase starch content and decrease the contents of soluble sugars and reducing sugars. In addition, abnormal starch structure in transgenic maize was also observed by scanning electron microscopy (SEM). Furthermore, the expression levels of starch synthesis-related genes were up-regulated in ZmDOF36 -expressing transgenic maize. ZmDOF36 was also shown to bind directly to the promoters of six starch biosynthesis genes, ZmAGPS1a , ZmAGPL1 , ZmGBSSI , ZmSSIIa , ZmISA1 , and ZmISA3 in yeast one-hybrid assays. Transient expression assays showed that ZmDOF36 can activate the expression of ZmGBSSI and ZmISA1 in tobacco leaves. Collectively, the results presented here suggest that ZmDOF36 acts as an important regulatory factor in starch synthesis, and could be helpful in devising strategies for modulating starch production in maize endosperm.

Genome-Wide In Silico Identification and Comparative Analysis of Dof Gene Family in Brassica napus

“…In cereals, Dof genes play a role in seed protein accumulation and mobilisation [ 60 , 77 , 78 ]. In maize, ZmDof36 and ZmDof3 play a role in seed starch accumulation [ 79 , 80 ]. However, for B. napus, the accumulation of oil in the seeds is of economic importance.…”

Genome-wide characterization and expression analysis of theDofgene family related to abiotic stress in watermelon

“…For example, ZmDof3 was found to be exclusively expressed in the endosperm of maize kernel and participate in the regulation of starch accumulation and aleurone development in maize endosperm (Qi et al, 2017). Another maize Dof gene ZmDof36 was also reported to be highly expressed in maize endosperm and function in starch synthesis by regulating the expression of starch synthesis genes (Wu et al, 2019). In this study, ClDof2, ClDof5, ClDof8, ClDof21 and ClDof35 showed much higher expression in leaves than in other tissues, suggesting that they play essential roles in leaf development.…”

Era-like GTP protein gene expression in rice

“…Type I starch synthesis genes is negatively associated with APETALA2/ethylene-responsive element binding protein family transcription factor encoded by Rice Starch Regulator1 (RSR1) (Fu and Xue 2010). RSR1 gene over-expression suppressed the starch production genes, whereas in rsr1 mutants the amylose content was increased (Wei et al, 2017;Wu et al, 2019). Furthermore, RSR1 regulates seed size; yield isolated and characterized the genes controlling pericarp color, nutritional quality, storage time and rice fragrance.…”

“…The toxins are only useful to identify the presence of certain classes of G proteins in an extract (Ying et al, 2018). GTP binding proteins which are not substrates for the toxin catalyzed ADP ribosylations (Wu et al, 2019). Immunoblot method using antisera against peptides from known G proteins have also been very powerful (Hsing et al, 2007).…”