Small Heat Shock Protein Expression In Tomato Anther And Ovary

Ths paper discussed the normal and heat shock expression of tour types of sHsps in tomato anther and ovary at different developmental stages. Tomato v.c XiFen III plants were grn in the field in the normal season. The fiers were treated for 2fr at different heat stress temperature of 31CC, 34CC, 37 C, 400C and 43C and then extracted the proteins. Because anthers aid ovaries at morphology and pollen tetrads stages were too small in size to be separated, they were collected together as plant matenafs, but the anthers and ovanes at other developmental stages were collected separately. E. Coli BL2I contains (His)6 labeled Hsp2l .3 pET27B(-i-) expressn plasmid was cultured aid the protein was induced by IPTG. After the protein was purified with Ni2 affinity chromatography, it was linked nUi BSA by Glutaraldehyde, and then used as antigen to prepare antiserum. Western-Blot method was used to detect sHsps?developmental expression. The results shcMed that four types of sHsps had different expression patterns. (1) Class I sHsp expressed in aithers and ovaries at every stage, and the protein in ovaries was a little more than that in anlhers. The results indicated that Class I sHsp might have much more important roles, and the mechanisms of the expression regulation were different between anther and ovary. (2) Class II sHsp was only detected at morphology establishment, pollen tetrads and monocellular pollen grains stages. This meant that Class II sHsp expression pattern was different from that of Class I sHsp. (3) It was the first time to get the information that Class MT sHsp existed during the morphology estallishment and pollen tetrads stages, and appeared only in the anthers during the folloMng stages. (4) Class ER sHsp dich express at the normal temperature. From the results above we kn Class I, Class II aid Class MT sHsps were developmental expression proteins, but Class ER sHsp was not Four types of sHsps were all induced by 31 C whkh was bier than the heat induce temperature of sI-Isps in leaves. The expression enhanced wi-iib the heat shock temperature inc-eased, and the sHsps acxajmulated to the highest level at 4O, then decreased at 43C. It seemed that 4CXC was a ttming pant for the expression to decrease. (1) At 43C Class I sHsp decreased more than Class II sHsp, suggesting that Class II sHsp might protect the ficers ftom damage occumng at higher heat-stress temperature than did the Class I sHsps. (2) At 31 C, the amount of Class II sHsp in ovaries was higher than that in anthers, suggesting that the heat response of ovar/s was stronger than that of anth&s. (3) The expression of Class ER sHsp at 31 0C and 340C was little, and it could be dearly detected at 3TC. At 400C, its expression reached the peals and decreased at 43C. To sum up all of the above, the heat stress expression patterns were similar, indicating that the heat stress regulation mechanisms were also resemble.