A Study On The Relation Between Leafy Trait And LFY Homologs In Maize (Zea Mays L.)

LFY gene was one of the central flower meristem identity genes inArabidopsis .The lfy mutants showed flower meristem could alter to anthotaxy branch, and it might lead to late-flowering and the variance of the leaf trait. In this paper, we studied the objective fragment length polymorphisms of LFY homologs(ZFL1) with leafy inbred lines and normal inbred lines by PCR in maize and cloned the related fragment .On the basis of the results, we discussed the relation between leafy trait and LFY homologs(ZFZ1) , and it was helpful to explore the flowering modulation mechanism of LFY homologs in maize, and to utilize leafy trait in silage maize breeding.Total DNA was extracted from young leaves of different maize inbred lines in fourth leaf stage. Those inbred lines had different leaf number above the ear, they were named as Y53(17L), Y53(4L), P175(10L), P175(4L), Mol7(4L).Five primers covering most ZFLl segments were designed according to a 2816 bp ZFL1 sequence to amplify objective fragments. We analyzed objective fragment length polymorphisms with different genetic background by agarose electrophoresis. Based on the results ,we amplified four objective fragments from Y53(14L), Y53(4L) by nested PCR, then isolated and sequenced PCR products .After connecting four objective fragments, We compared the sequence with publicize sequence by database. On the basis of these results, we explored the inherent unification between the genetic mechanism of maize leafy characteristic and the expression and regulation of ZFL1 gene.The results as followed:1.The analysis of PCR product showed that objective fragment 1 and 3 had not length polymorphisms among different inbreds with diverse leaves above the ear. The length of objective fragment 2 amplified from Mo17(4L) by PCR was 535bp . Because of the absence of intron 1, fragment 2 from Mo17(4L) was 291bp shorter than objective fragments from other materials. Owe to objective fragment 4 lied in the intron 2, the diversity of objective fragment 2 had no influence on the expression of gene. A 517bp fragment from template DNA of P175(4L), P175(10L). Y53(4L) and Y53(17L) could be amplified .Template DNA of Mo17(4L) could amplify a 826bp fragment , but the length of objective fragment was 677bp. PCR products of objective fragment 5 from different materials with diverse leaves above the ear and different genetic background appeared fragment length polymorphism. Objective fragment 5 could not be amplified in leafy maize material: Y53(17L), P175(10L). On the contrary, it could be amplified in comparison materials with four leaves above the ear : Y53(4L), P175(4L) and M017(4L). 2. Compared with Y53(4L), the mutation frequency of Y53(14L) in the ZFL1 gene locus were high. A 13bp repeat sequence in exon 3 locus caused to reading-frame shift and the alert of amino acid sequence. These suggested expression products of LFY homologs(ZFL1) were different between leafy inbred line and inbred line with four leaves above the ear in maize.According to these results, we speculated that the mutation in the ZFLl gene exon3 locus led to the loss of function of expression product, which was the transcription factor binding site, and the mutation led to the delay of vegetative stage and increase of leaf number above the ear.