Use of a novel R2R3-MYB transcriptional activator of anthocyanin biosynthesis as visual selection marker for rubber tree (Hevea brasiliensis) transformation
Use of a novel R2R3-MYB transcriptional activator of anthocyanin biosynthesis as visual selection marker for rubber tree (Hevea brasiliensis) transformation
复制标题
使用花青素生物合成的新型 R2R3-MYB 转录激活剂作为橡胶树（Hevea brasiliensis）转化的视觉选择标记
DOI：
10.1016/j.indcrop.2021.114225
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发表时间：
2021-11-03
影响因子：
5.9
通讯作者：
Hua, Yuwei
中科院分区：
文献类型：
--
作者：
Huang, Tiandai;Xin, Shichao;Hua, Yuwei
巴西橡胶树是目前唯一的天然橡胶商业来源。利用花色素苷的产生作为一个视觉和非破坏性的选择标记，可能是一个可行的策略，提高转化效率的这一物种。在这项研究中，高效液相色谱（HPLC）分析证实，花青素型花青素是橡胶树组织中红色的主要决定因素。茉莉酸甲酯（MeJA）处理可以激活橡胶树体细胞胚花青苷的合成。通过序列比对和系统发育分析，获得了一个新的橡胶树R2 R3-MYB转录因子（TF），命名为橡胶树花青素2（HbAN 2）。HbAN 2的表达与橡胶树组织中的花青素含量密切相关。HbAN 2在花青素苷生物合成中的调节作用在天然和异源系统中进行了功能表征。在烟草悬浮培养细胞中，HbAN 2单独或与两个HbbHLH基因组合表达激活了负责花青素苷生物合成的关键基因NtDFR的启动子。在烟草植物和橡胶树胚中，HbAN 2的过表达上调了后期花青素苷途径基因，导致外植体的转化部分中花青素苷积累增加，因此很容易与非转化部分区分开来。虽然转基因橡胶树芽未能再生成完整植株，这些结果表明HbAN 2是花色素苷生物合成的调节剂，并有可能用作橡胶树转化的视觉选择标记。
Hevea brasiliensis is presently the only commercial source of natural rubber. The use of anthocyanin production as a visual and non-destructive selection marker may be a viable strategy for increasing the transformation efficiency of this species. In this study, high performance liquid chromatography (HPLC) analysis confirmed that the cyanidin-type anthocyanin is a major determinant of red color in Hevea tissues. It was also found that the anthocyanin production in Hevea somatic embryos could be activated by methyl jasmonate (MeJA) treatment. By sequence alignment and phylogenetic analysis, a novel Hevea R2R3-MYB transcription factor (TF) was isolated and designated here as Hevea brasiliensis Anthocyanin 2 (HbAN2). The expressions of HbAN2 correlate well with the anthocyanin levels in Hevea tissues. The regulatory roles of HbAN2 in anthocyanin biosynthesis were functionally characterized in the native and heterologous systems. In tobacco suspension culture cells, the expression of HbAN2 alone or in combination with two HbbHLH genes activated the promoter of NtDFR, a key gene responsible for anthocyanin biosynthesis. In tobacco plants and Hevea embryos, overexpression of HbAN2 upregulated the late stage anthocyanin pathway genes, resulting in increased anthocyanin accumulation in the transformed parts of the explants, which were therefore easily distinguishable from the non transformed parts. Although transgenic Hevea shoots failed to regenerate into whole plants, these results suggest that HbAN2 is a regulator of anthocyanin biosynthesis and has the potential to be used as visual selection marker for Hevea transformation.