The Expression And Genetics Of BoCAL Gene In Cauliflower

CAL(cauliflower) gene is an important and special floral developmental gene,and encodes a protein(30kDa),which consists of 255 amino acids.Cauliflower (Brassica oleracea var. botrytis L.) and cabbage (B. oleracea var capitata Z.) are two varieties of species B.oleracea. Cauliflower bobcal gene loses its original function due to its terminated mutation while cabbage BoCAL gene has its complete function. The introduction of cabbage BoCAL gene into cauliflower may bring great influence to the expression of the mutated bobcal gene and cause the alteration of curd phenotype. This research was carried out on T2 generation of transgenic BoCAL cauliflower lines, which as main material, to study the expression and genetics of BoCAL gene. And the results as following:1. All the plants of T1, T2 and T3 generations of transgenic cauliflower lost the ability to form curd.Their "curds" did not stop at developmental stage of apical meristem,but produced loose,green inflorescence,which composed of flower buds instead,not floral meristem.At beginning,the curd was also white,size as thumb, but quickly turned into yellow and green.At this time,the plants entered into the stage of inflorescence.The transgenic cauliflowers for BoCAL had more trend to form heads than controlling cauliflower, manifesting their different abilities to form heads.It demonstrated that cauliflower bobcal was complemented by cabbage BoCAL gene,such resulted in cauliflower lost its ability to form curd.2.Controlling cauliflower began its iniatiative of inflorescence at 180d after sowing,delayed 45d than transgenic cauliflowers;accordingly,the iniatiative day of inflorescence and flowering of the hybrids of control and transgenic cauliflowers was between its parents.So BoCAL gene had function to promote the development of inflorescence and to advance the flowering day of transgenic cauliflowers.3.The genetics of T2 transgenic cauliflower indicated that the index of leaf shape(ILS) was segrated at mendelian ratio of 1:2:1 according to 0 1.5.Developing types was also segregated at ratio of 3:1 according to H(phenotype of cauliflower), HG(phenotype of cabbage with cauliflower) and GH(phenotype of cauliflower with cabbage).The same segregating pattern also happened in leaf color(dark, middle and light green) ,the ability to form head(head, half-head and non-head). All the segregation indicated that BoCAL gene had complemented to cauliflower demestic bobcal gene.The margin of leaf(undulated , no-undulated),the inner leaf (no-screwed, screwed ) were segrated at mendelian ratio of 3:1.The outer leaf (reversed , no-reversed) was segrated at ratio of 3:1 in Pl(transgenic cauliflower linel) and P2(transgenic cauliflower line 2),but not in P3(transgenic cauliflower line 3).The phyllosphere(smooth , wrinkle), stalk and growing apex(green , purple),leaf(whole lamina and non-lamina) were all segrated at ratio of 1:1. But the shape of leaf(rotund, awl-shaped and oval), wax(heavy, middle, light) were not segrated at mendelian ratio of 1:2:1 or 3:1.4.There were some polymorphism, indicating the diversiform functions of BoCAL gene and its genetic complexity.5.PCR , Southern blotting and selection on kanamycin medium indicated that BoCAL gene had single-sited integrated into cauliflower and conformed to the segregation of single-dominant gene by the law of Mendelian Inheitance.