Functional marker related to germination vigor of maize seed.

Germination and synchronous seedling emergence are necessary for crop yield. One differentially expressed Cupin protein during maize seed germination had been identified in our previous study. To elucidate the functional sites in its coding gene, ZmGLP, a diverse maize association population was assayed. In alignment with B73, the ZmGLP gene contains five exons and encodes 522 amino acids, and a potential signal peptide domain from the 7 to 22 amino acids and a typical Cupin domain from the 332 to 477 amino acids were identified. The ZmGLP has a quick linkage disequilibrium decay with about 300 bp physical distance in the analyzed sequences, which implied that human selection might be undone in this gene. High genetic variations were evidenced in ZmGLP gene with 118 polymorphic sites in the association population. An Indel9 (18 bp) in the fifth exon of the intermotif region of the second Cupin domain, which influences the formation of C coil in the barrel folding, was detected significantly associated with germination vigor of maize seeds. The 18-bp insertion, which might help keeping the barrel folding intact, was a favorable allele for relative high germination vigor. Evolution analysis showed that this 18-bp deletion was a loss-of-function mutation. However, the action mode of ZmGLP is still yet to be further studied for maize improvement. [ABSTRACT FROM AUTHOR]