Screening And Gene Mapping Of Pavement Cell Defective Mutant Nal And Abnormal Petal Mutant Apn In Arabidopsis

In multicellular systems,the research about jigsaw puzzle appearance of Arabidopsis pavement cells has been a hotspot in plant science.In the previous studies,we obtained a dwarf and pavement cell defective mutant named topp4-1 by EMS-mutagenized population.In order to further study the function of TOPP4 in pavement cell morphogenesis,we conducted a secondary mutation of topp4-1 by EMS mutagenesis treatment.By using synthetic resin teeth imprinting technique to observe the pavement cell of rosette leaf of each mutation strain plant,we screened a mutant named nal+/-topp4-1 with pavement cell shape changed.The nal+/-topp4-1 double mutant enhanced the dwarfed phenotype of topp4-1 with smaller and sharper leaf,and the margins of leaves become serrated significantly;by the observation of the pavement cell of nal+/-topp4-1 double mutant,it found that that the pavement cell morphology similar to topp4-1 which also showed smaller cells,fewer number of lobe,shorter lobe length and simpler shape.We obtained the nal single mutant by cross to wild type,Col.We found that rosette leaves of three weeks old nal single mutant were curl with sharpened tip and serrated wavy margin;by synthetic resin teeth imprinting technique,it found that the epidermal cells morphological changed with fewer lobe number,longer lobe length appear,larger average epidermal cell area,and simpler cell shape.By mapping based coning,it found that NAL gene was located on the left of chromosome 1 which encodes protein similar to splicing protein,Snu 114 and may involve in the activity of the spliceosome.The study also studied the response of nal mutant to the exogenous hormones PAC,GA,IAA;the results indicated that the hypocotyls length is more sensitive to exogenous PAC and insensitive to exogenous GA;and the root length is more sensitive to exogenous IAA.Flowers as the most prominent organ in flowering plants,its shape,structure,color,etc.are all specific.Its structure from the inside to the outside can be divided into four concentric floral organs which are pistil,stamens,petals and sepals.' Currently,genes involved in floral organ development include the mainly related genes in ABC model(AP1,AP2,AP3,etc.).Arabidopsis belongs to cruciferous plants;its flowers have four petals.And currently,it has reported that ROXY1,FRL1,PGX1 etc.are involved in the regulation of Arabidopsis flower petals.Mutagenesis by EMS,we screened an abnormal number of petals mutant named apn which appear 3-8 pieces of petals;the arrangement of the distribution of the petals are also abnormal.By map-based cloning,we found the gene locate at the right end of chromosome 1 with a total length of 215 Kb.