A comparison of the physicochemical properties, digestibility, and expression patterns of starch-related genes of two supersweet corn hybrids (F1) and their parents.

The quality difference of corn largely depends on parental selection. Herein, the structure, digestive characteristics, and expression patterns of starch-related genes of two supersweet maize hybrids and their parents were studied. The structural analysis revealed that the starch of supersweet corn is round or oval, and the particles are smaller compared to those of normal corn. Hybridization changed the grain morphology, crystal, and helical structure of starch. Parents had a significantly different influence on supersweet corn. Notably, hybridization improved the setback value and digestibility of Shantian1500F1 and Shantian2000F1 compared to that of the parents. ZmBEI, ZmPHOH, and ZmAGPL2 genes had a consistent high expression throughout the whole grain formation phase. The results of this study expand our understanding of the breeding of supersweet corn hybrids and the effect of parents on the new strand. These results provide a useful reference for further breeding and studies of supersweet corn for starch production in corn.

ZmSMR10 Increases the Level of Endoreplication of Plants through Its Interactions with ZmPCNA2 and ZmCSN5B.

As a plant-specific endoreplication regulator, the SIAMESE-RELATED (SMR) family (a cyclin-dependent kinase inhibitor) plays an important role in plant growth and development and resistance to stress. Although the genes of the maize (Zea mays) SMR family have been studied extensively, the ZmSMR10 (Zm00001eb231280) gene has not been reported. In this study, the function of this gene was characterized by overexpression and silencing. Compared with the control, the transgenic plants exhibited the phenotypes of early maturation, dwarfing, and drought resistance. Expression of the protein in prokaryotes demonstrates that ZmSMR10 is a small protein, and the results of subcellular localization suggest that it travels functionally in the nucleus. Unlike ZmSMR4, yeast two-hybrid experiments demonstrated that ZmSMR10 does not interact strongly with with some cell cycle protein-dependent protein kinase (CDK) family members ZmCDKA;1/ZmCDKA;3/ZmCDKB1;1. Instead, it interacts strongly with ZmPCNA2 and ZmCSN5B. Based on these results, we concluded that ZmSMR10 is involved in the regulation of endoreplication through the interaction of ZmPCNA2 and ZmCSN5B. These findings provide a theoretical basis to understand the mechanism of the regulation of endoreplication and improve the yield of maize through the use of molecular techniques.