Duck N B, Folk W R
Department of Biochemistry, University of Missouri, Columbia 65211.
Plant Mol Biol. 1994 Nov;26(4):1031-9. doi: 10.1007/BF00040686.
Pollen of angiosperms lacks the ability to respond to heat stress by synthesizing heat shock proteins (hsps). In tomato developing microspores were found to have 70 kDa heat shock proteins (hsp70s) present throughout development, even in the absence of heat stress. Heat shock protein family members expressed in the absence of heat stress are called cognate (hsc70) genes. Antisense RNA and antibody probes were used for in situ hybridizations which detected hsc70 expression in developing pollen of immature buds. Hsc70 mRNA transcripts and proteins were detected in nonstressed sporogenous tissues, microspores and in pre-tapetal layers during early pollen development. While immunoblot analysis detected hsc70 proteins stored in mature pollen, heat stress could not induce the synthesis of new hsp70 protein as measured by 35S-methionine labeling followed by immunoprecipitation.
被子植物的花粉缺乏通过合成热休克蛋白（hsps）来应对热胁迫的能力。在番茄中，发现发育中的小孢子在整个发育过程中都有70 kDa热休克蛋白（hsp70s），即使在没有热胁迫的情况下也是如此。在没有热胁迫时表达的热休克蛋白家族成员被称为同源（hsc70）基因。反义RNA和抗体探针用于原位杂交，检测未成熟花蕾发育中的花粉中hsc70的表达。在早期花粉发育过程中，在未受胁迫的造孢组织、小孢子和绒毡层前层中检测到了Hsc70 mRNA转录本和蛋白质。虽然免疫印迹分析检测到成熟花粉中储存有hsc70蛋白，但通过35S-甲硫氨酸标记随后进行免疫沉淀测定，热胁迫并不能诱导新的hsp70蛋白的合成。
