Construction And Characteristics Analysis Of Oryza Sativa Phytosulfokinase Genes Ospsk3 And Ospsk5 Transformed Oryza Sativa

In animals and bacterium, there are a large number of polypeptides who serve as hormones, pheromones and growth factors. Significantly, they play a physiological function in regulation and growth. However, in plant kindom, no one in the five well-known hormones besides auxin, cytokinin, gibberellin, abscisic acid and ethylene is bioactive peptide at all, as well as brassinolide and jasmonic acid discovered later. Until Systemin was discovered in 1991, then Phytosulfkine, CLAVATA3 (CLV3), SCR/SP11 and other small plant peptides were demonstrated had played an exclusive role in plant growth, development and signal transduction. The emergence of small peptides opened a new era in signal transduction pathway in plant. The discovery of phytosulfokine, a bioactive small sulfonated peptide showed its ability to stimulate suspended cell mitosis and promote cell growth in culture under low concentration less than ever.Two new members of rice PSK family were named as OsPSK6 and OsPSK7 via sequence analysis and comparison, and their expression in different tissues was also detected. Based on all 75 PSK protein in plant, we summerized a conserved signature motif, which reads:Cx0-4Gx0-2[E/D]1-5C[L/F/I/M/V]1-3[R/K]1-3[N/T/S]0-1[L/F/I/M/A]1-3AH[L/V/ T]DYIYTQWe amplified rice PSK family genes OsPSK3 and OsPSK5 from Nipponbare Japonica callus cDNA pool. Two genes were then cloned into Carnahan penicillin resistant plant expression vector cambia 1304 using the method of particle bombardment transformation and material of Indica variety 9311 calli as receptor. 10 OsPSK3 To seedlings and 12 OsPSK5 To seedlings were screened through Carnahan penicillin resistance assay. Finally 4 seedlings in OsPSK3 line and 7 seedlings in OsPSK5 line were verified positive via PCR detection.We observed seedlings of OsPSK3 and OsPSK5 T1 generation in incubation chamber, and found them exceled in vegetative growth. They growed more roots and root hairs and increased chlorophyll content in leaves at the rate of 2.3 times and 1.8 times compared to CK respectively. OsPSK3 can grow taller than CK from the very begining of seedling stage to the end of heading stage. Meanwhile, OsPSK5 line possessed broader leaves.