Regulation And Molecular Mechanism Of ZmNF-YC13 Transcription Factor On Maize Plant Architecture

Maize(Zea Mays L.)is one of the most important crops,with a global planting area and a great potential for increasing yield.It plays an irreplaceable role in Chinese agriculture.Plant architecture is one of the most factors affecting the yield of maize.Therefore,cultivating maize varieties with excellent plant architecture is the top priority in agriculture,and also the primary goal of breeding in China.Leaf angle(LA)and leaf orientation value(LOV)are critical agronomic traits for maize plant architecture.With erect leaves and compact plant architecture,the plants with smaller Angle have less shading between each other,which is beneficial to the accumulation of photosynthates.The increase of ventilation between populations increases the number of plants per unit and the yield per unit.NF-Y is a class of transcription factors widely found in plants and mammals.It is composed of three subunits,NF-YA,NF-YB,and NF-YC.Each of these subunits has an independent role and can interact with each other to form complex to regulate plant growth and development,salt tolerance regulation,drought resistance regulation,and development of grains.Many genes which are related to plant architecture have been identified in maize,but the functions of NF-Y members in regulating plant architecture have not been reported yet.This study mainly discussed the functions and regulation pathway of ZmNF-YC13,a transcription factor,on maize plant architecture development,and also discussed the mechanism of the interaction between ZmNF-YC13 and ZmNF-YB9/10,and the mechanism of plant architecture development in maize may be regulated by the compound.The main results were as follows:1.The ZmNF-YC13 gene was segmentally extracted from the third leaf of maize leaf with transgenic material.The quantitative analysis test indicated that ZmNF-YC13 was highly expressed in the leaf base zone of maize plants.2.Compared with the wild type,the over-expression of ZmNF-YC13 inhibited the growth of maize leaves at seedling stage.On the contrary,the knockout of ZmNF-YC13 accelerated the growth of maize leaves at seedling stage.3.Phenotypic analysis of ZmNF-YC13 showed that compared with the wild type,the overexpression of ZmNF-YC13 made the plant leaves more upright and compact with a smaller leaf Angle and larger leaf direction value at the mature stage.On the contrary,the knockout of ZmNF-YC13 made the plant leaves more spread with a larger leaf angle and smaller leaf direction value.4.Transcriptome sequencing using wild-type and overexpressed leaves revealed a total of 265 differentially expressed genes(fold change>2,FDR<0.01),including 117up-regulated genes and 148 down-regulated genes,compared with wild-type leaves.KEGG pathway analysis showed that the differentially expressed genes were mainly concentrated in the phenyl propionic acid synthesis pathway,and were mainly cytochrome P450 family protein-coding genes.Among the P450 coding genes,ZmCYP78A6,ZmCYP81F4,ZmCYP81E1,ZmCYP81E2,and ZmCYP81E3,were in a similar evolutionary branch to the maize PLA1 gene.Their expression levels were significantly down-regulated in the overexpression materials and up-regulated in the knockout materials.5.Further analysis showed that compared with the wild type,the expression levels of ZmCYP78A6,ZmCYP81F4,ZmCYP81E1,ZmCYP81E2,and ZmCYP81E3,were down-regulated in leaf sheaths,leaf sheet-leaf junctures,and leaves of the overexpressed plants.On the contrary,in the knockout plants,the expression levels were up-regulated in these parts.6.The yeast two-hybrid,BIFC test,and Pulldown test showed that ZmNF-YC13 could interact with ZmNF-YB9/10.