| In order to elucidate the effect of heat stress on pollen development and fertilization in cucumber(Cucumis sativus L.), Ca2+ distribution(using potassium antimonite precipitate method), ABA contents and protein synthesis patterns in uninucleate-binucleate-pollen-phase anthers of cucumber heat-tolerant line JY-4 and heat-sensitive line Xintaimici, and in stigma and ovaries of Xintaimici after pollination, were investigated under 45 Cand 28 C. We also studied the effect of exogenous Ca2+and ABA on anthers and stigma , ovaries after pollination of cucumber. The results showed that:I Under 45 C treatment, Ca2+ precipitates increase in pollen and anther cells of both lines, more quickly in Xintaimici than in JY-4. While the temperature recover to 28 C after 45 C stress, the Ca2"1" precipitates quantity drop to the normal level more tardily in Xitaimici anther cells. Endogenous ABA contents in two line anthers also ascend significantly after Ih 45 C treatment, especially in Xintaimici. When the environment return to 28 C, ABA in Xitaimici anthers step down to the control level, while JY-4 anthers can maintain a higher ABA content within 2h. No any additional protein points can be seen in the IEF-SDS-PAGE maps of cucumber anthers in this stage under 45 C stress comparing with 28 C, although the expression of some proteins, such as MW70KD(PI5.7) and MW45.5KD(PI5.6) were upregulated remarkably after heat treatment(even higher in JY-4 than in Xintaimici). The results indicated that both Ca2+ and ABA signals were involved in the response of cucumber anthers to heat-stress. The synthesis of HSPs in cucumber uninucleate-binucleate-pollen-phase anthers were at least in part inhibited under heat treatment, it maybe an important reason why cucumber anther is sensitive to hightemperature during this stage.II Under 45 C treatment, Ca2+precipitates increase in both apoplast and cytoplasm of stigma tissues, and little Ca2+ quantity difference can be seen between apoplast and cytoplasm comparing to the 28 C, under which there are more Ca2+ precipitates in apoplast than in cytoplasm. Endogenous ABA contents in stigma and ovaries also ascend significantly after Ih 45 C treatment. Some additional protein points can be seen in the IEF-SDS-PAGE maps of stigma and ovaries after 45 C stress comparing with 28 C, such as proteins MW26.0KD(PI5.4), MW90.0KD (PI5.1 X MW54.0KD (PI4.6), MW41.0KD (PI6.2) in stigma andMW90.0KD (PI5.2X MW61.0KD (PI5.4), MW48.0KD (PI6.4X MW40.5KD (PI4.9) in ovaries. Furthermore, the expression of proteins MW67.0KD (PI5.8 ) ,MW56.5KD (PI5.8) in stigma andMW70.0KD(PI5.7),MW57.0KD(PI5.7)in ovaries were upregulated remarkably after heat treatment. The results indicated that both Ca2+ and ABA signals were involved in the response of cucumber female reproductive organs to heat-stress and then change the gene expression.IIIUnder 45 C, Exogenous Ca2+ reduce the intercellular Ca2+ of cucumber anthers and increase the pollen germination percentage at high temperature, while the exogenous ABA have a reverse effect. Endogenous ABA contents in two line anthers ascend significantly linked with new proteins formation after exogenous Ca2+ and ABA treatment under 45 C, such as proteinMW56.0KD(PI5.1) in both Xitaimici and JY-4, MW92.5KD (PI5.2) in Xitaimici, MW58.0KD (PI5.3) andMW92.5 (PI5.5) in JY-4 after Ca2+treatment. AndMW46.0 (PI6.0) in Xitaimici, MW56.0KD (PIS. 1) in JY-4 after ABA treatment. The results indicated that Ca2+ and ABA signals can interact each other in cucumber uninucleate-binucleate-pollen-phase anthers under high temperature.IV Ca2+ distribution(using potassium antimonite precipitate method), ABA contents and protein synthesis patterns in pollinated stigma and ovaries of cucumber Xintaimici were investigated under 45 Cand 28 C after exogenous Ca2+ and ABA treatment. Under 45 C, Exogenous Ca2+ reduce the intercellular Ca2+ of cucumber stigma andovaries after pollination, while the exogenous ABA have indistinctive effect. Endogenous ABA contents in stigma and ovaries reduced significantly linked w...
|
PDF Full Text Request