Differential Gene Expression Analysis of Yunnan Red Pear, Pyrus Pyrifolia, During Fruit Skin Coloration
Differential Gene Expression Analysis of Yunnan Red Pear, Pyrus Pyrifolia, During Fruit Skin Coloration
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云南红梨、梨果皮着色过程中差异基因表达分析
DOI：
10.1007/s11105-010-0231-z
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发表时间：
2011-06-01
影响因子：
2.1
通讯作者：
Su, Jun
中科院分区：
文献类型：
--
作者：
Zhang, Xiaodong;Allan, Andrew C.;Su, Jun
果皮颜色是一个重要的品质参数，在许多植物中，它是花青素途径协调调节的结果。为了研究云南红梨果皮变色的机制，利用抑制消减杂交技术构建了一个消减cDNA文库。将暴露在阳光下（2、4、6和8天）的红色果皮的cDNA与未暴露在阳光下的白色果皮的cDNA相减。获得了100多个差异表达的ESTs，推测它们参与了初级和次级代谢、应激和防御反应。采用半定量反转录聚合酶链式反应（RT-PCR）分析了13个基因的表达，分别用浅皮‘枣白米’和红皮‘云红1号’2个梨品种，在收获前进行套袋处理，分别在日光下晒0、1、2、3、5和7 d。这一分析表明，编码金属硫蛋白样蛋白和nadp -苹果酸酶的基因是组成性表达的，而其他选择的基因要么是下调的，要么是上调的。对7个花青素生物合成途径基因和3个推测的调控基因进行了半定量RT-PCR分析。结果表明，色色较差的“枣白米”和色色较好的“云红1号”在脱袋后均上调了R2R3 MYB转录因子PyMYB10，但其表达动力学在不同品种间存在差异。其他花青素相关基因似乎由MYB-bHLH-WD40复合物协调调节。DFR和ANS基因似乎是颜色较差的枣白米梨果皮颜色的限制因素，而红果除袋后7 d，所有生物合成步骤都上调。本研究表明，红梨颜色的调控是通过MYB-bHLH-WD40复合物对梨花青素途径基因的差异作用来实现的。
The color of fruit skin is an important quality parameter, and in many plants, it is the result of coordinative regulation of the anthocyanin pathway. To characterize the mechanism involved in fruit peel coloration of Yunnan red pear (Pyrus pyrifolia), we constructed a subtractive cDNA library using the suppression subtractive hybridization (SSH) technology. cDNA of red peel exposed to sunlight (for 2, 4, 6, and 8 days) was subtracted from that of white skin unexposed to sunlight. Over 100 differentially expressed ESTs were obtained, putatively involved in primary and secondary metabolism, stress, and defense response. Expression analysis using semiquantitative reverse transcription polymerase chain reaction (RT-PCR) for 13 genes was performed with two pear cultivars, light-skinned ‘Zaobaimi’ and red-skinned ‘Yunhong-1’, which had been bagged and then exposed to sunlight for 0, 1, 2, 3, 5, and 7 days before harvest. This analysis showed that genes encoding for a metallothionein-like protein and a NADP-malic acid enzyme were constitutively expressed, whereas other selected genes were either down- or up-regulated. Semiquantitative RT-PCR analysis for 7 anthocyanin biosynthetic pathway genes and 3 putative regulatory genes was also performed. Results showed that an R2R3 MYB transcription factor PyMYB10 was up-regulated in both the less-colored pear ‘Zaobaimi’ and well-colored red pear Yunhong-1 after the bag was removed, but that kinetics differed between cultivars. Other anthocyanin-related genes appeared to be coordinately regulated by the MYB–bHLH–WD40 complex. DFR and ANS genes seemed to be limiting factors for the peel coloration of less-colored pear ‘Zaobaimi’, while all biosynthetic steps are up-regulated by 7 days after bag removal in red fruit. This study suggests the regulation of red pear coloring is via differential effects of the MYB–bHLH–WD40 complex on the pear anthocyanin pathway genes.