摘要：




以单细胞和小细胞团二种悬浮培养体系为材料，利用反转录PCR技术（RT-PCR），研究了毛白杨初生和次生细胞壁形成中若干相关基因的差异表达，包括与细胞伸展、纤维素合成、木质素合成等有关的12个基因。结果表明：3 个伸展酶基因（α-Exp）在单细胞悬浮细胞系中均有大量表达，其中α-Exp2 最高，其次为α-Exp3，表明处于旺盛的细胞伸展期，而小细胞团悬浮细胞系只有α-Exp3 的表达相对较强，表明处于细胞伸展后期或次生壁形成初期；在6 个纤维素合成相关基因中，2 种悬浮细胞系均有较高的CesA4 和CaSy1 表达，并且CesA1、CesA3-1 和CesA3-2 也有一定表达，表明它们均有不同程度的初生壁形成，但CesA3-1 和CesA3-2 的表达在小细胞团中相对较高，推测它有相对较多的纤维素合成和初生壁形成；2 种悬浮细胞系中均未检测出Lac1 和Unk1 基因的表达，推测均没有木质素的大量合成和次生壁的完整发育。Abstract: With fine and granular suspension cultures established from P. tomentosa, differential expression of 12 genes related to cell wall formation including cell expansion, cellulose synthesis, lignin synthesis, etc, were investigated by reverse transcript PCR (RT-PCR) technique. Fine suspension cells showed high expression on 3 α-Exp genes with the highest α-Exp2 followed byα-Exp3 and α-Exp1 suggesting their strong cell expansion, while granular suspension cells only exist high expression on α-Exp3 indicating their later period
of cell expansion or initial stage of secondary cell wall formation. Among the 6 genes relating to cellulose synthesis, both fine and granular cultures have high expression on CesA4 and CaSy1 and some expression on CesA1、CesA3-1 and CesA3-2, indicating their primary cell wall formation initiated, however a little higher expression on CesA3-1 and CesA3-2 in granular cells may reflect its more cellulose synthesis and more primary cell wall formation. The occurrence of Lac1 and Unk1 could not been detected in the 2 cell suspension cultures, showing no significant lignin biosynthesis and matural secondary cell wall formation.