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.
Highlights
Maize (Zea mays L.) is one of the most important food and feed crops in the world and has enormous economic and biological significance (Wu and Messing, 2014)
Our results strongly suggest that ZmDOF36 may be involved in endosperm development
The DOF transcription factor (TF) family is a class of plant-specific TFs that are widely involved in plant growth, development, signal transduction, and the response to biotic and abiotic stress (Yanagisawa, 2002; Noguero et al, 2013)
Summary
Maize (Zea mays L.) is one of the most important food and feed crops in the world and has enormous economic and biological significance (Wu and Messing, 2014). With the completion of the maize genome sequence, it has become an important model organism for biological studies in addition to being a resource for food, fuel, and feed. Starch generally consists of two major fractions, linear amylose, and branched amylopectin (Morell and Myers, 2005; Tetlow, 2006). Amylopectin comprises about 75% of the starch, ZmDOF36 Regulates Maize Starch Synthesis whereas amylose accounts for 25%. In the past several decades, the starch metabolic pathways have been well characterized in a number of studies on the key enzymes involved in starch synthesis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
