Em polypeptide and its messenger RNA levels are modulated by abscisic acid during embryogenesis in wheat.
Em polypeptide and its messenger RNA levels are modulated by abscisic acid during embryogenesis in wheat.
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Em 多肽及其信使 RNA 水平在小麦胚胎发生过程中受脱落酸调节。
DOI：
10.1111/j.1432-1033.1985.tb09224.x
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Cuming,AC
中科院分区：
文献类型：
--
作者：
Williamson,JD;Quatrano,RS;Cuming,AC
在培养的未成熟小麦 (Triticum aestivum, L.) 胚、发育中胚和植物中的发育胚中检测了脱落酸 (ABA) 对“早期蛋氨酸标记”(Em) 多肽表达的影响。利用来自在 ABA 存在下培养的未成熟胚胎的富含 Poly(A) 的 RNA 构建了互补 DNA (cDNA) 文库。首先通过差异菌落印迹杂交鉴定 ABA 增强序列，然后使用 RNA 狭缝印迹分析进行验证。点印迹杂交表明，一个克隆 p1015 与之前分离的 EmcDNA pWG432 同源。 p1015 的混合选择翻译产物的电泳分析证实了其作为 Emsequence 的身份。根据 Northern 印迹分析，比较 p1015 cDNA 插入片段大小和 Emmessage 大小，结果表明 p1015 包含约 87% 的 Emsequence。 RNA 狭缝印迹分析和蛋白质电泳表明，在缺乏 ABA 的情况下，未成熟胚胎中 Emmessage（而非 Em Protein）以较低的基础水平积累。在三天发芽的幼苗中均未发现 Emmessage 和 Em Protein。在 ABA 存在的情况下，无论是在培养物还是在植物中，未成熟胚胎中 Emmessage 和蛋白质的稳态水平都会增加。监管似乎主要是在转录或特定信息稳定性水平上。调节还可能涉及特定的蛋白质稳定性，因为在没有 ABA 的情况下，未成熟胚胎中 Em Protein 的合成仍在继续，但 Em Protein 的积累量并未达到可检测的水平。我们得出结论，ABA 特异性调节未成熟胚胎中的 Emmessage 和蛋白质水平，但可能与 Emexpress 的胚胎发生特异性无关。
The effect of abscisic acid (ABA) on the expression of the ‘early‐methionine‐labeled’ (Em) polypeptide was examined in cultured, immature wheat (Triticum aestivum, L.) embryos and in developing embryos and in developing embryosin planta. A complementary DNA (cDNA) library was constructed from poly(A)‐rich RNA from immature embryos cultured in the presence of ABA. ABA‐enhanced sequences were first identified by differential colony‐blot hybridization, and then verified using RNA slot‐blot analysis. Dot‐blot hybridization showed that one clone, p1015, was homologous to the previously isolated EmcDNA, pWG432. Electrophoretic analysis of the hybrid‐select translation product of p1015 confirmed its identity as an Emsequence. Comparison of the p1015 cDNA insert size and the Emmessage size, from northern blot analysis, showed that p1015 contained about 87% of the Emsequence. RNA slot‐blot analysis and protein electrophoresis showed that Emmessage, but not Emprotein, accumulated at a low, basal level in immature embryos in the absence of ABA. Neither Emmessage nor Emprotein was seen in three‐day germinated seedlings. Steady‐state levels of Emmessage and protein increased in immature embryos in the presence of ABA, both in culture andin planta. Regulation appeared to be primarily at the level of transcription or specific message stability. Regulation may also involve specific protein stability, since synthesis of Emprotein continued in immature embryos in the absence of ABA, but Emprotein did not accumulate in detectable amounts. We conclude that ABA specifically modulates Emmessage and protein levels in immature embryos, but is probably not responsible for the embryogenic specificity of Emexpression.