Heng Wei, Wang Ziteng, Jiang Xianghong, Jia Bing, Liu Pu, Liu Li, Ye Zhenfeng, Zhu Liwu
College of Horticulture, Anhui Agricultural University, Hefei, Anhui, People's Republic of China.
Plant Cell Rep. 2016 Sep;35(9):1841-52. doi: 10.1007/s00299-016-1998-7. Epub 2016 Jun 3.
Differential genes of suberin, polyamine and transcription factors in transcriptome sequences and the contents of H 2 O 2 , spermidine, spermine, and putrescine changed significantly after treating with MGBG. Russeting is a commercially important process that restores the control of water loss through the skin via the formation of a waterproofing periderm just beneath the microcracked skin of pear primary fruit. A spontaneous russet skin mutant, the yellow-green 'Dangshansuli' pear, has been identified. To understand the role of polyamines in the formation of the russet skin of the mutant-type (MT) pear, it was treated with methylglyoxal-bis-(guanylhydrazone) (MGBG) for 4 weeks after full bloom. One week later, differentially expressed genes among the wild-type (WT), MT, and MGBG-treated MT pears were screened, hydrogen peroxide (H2O2) was localized using CeCl3, and the contents of H2O2 and polyamine were measured. A total of 57,086,772, 61,240,014, and 67,919,420 successful reads were generated from the transcriptomes of WT, MT, and MGBG-treated MT, with average unigene lengths of 701, 720, and 735 bp, respectively. Differentially expressed genes involved in polyamine metabolism and suberin synthesis were screened in 'Dangshansuli' and in the mutant libraries, and their relative expression was found to be significantly altered after treatment with MGBG, which was confirmed by real-time PCR. The expression patterns of differentially expressed transcription factors were identified and were found to be similar to those of the polyamine- and suberin-related genes. The results indicated that the H2O2 generated during polyamine metabolism might contribute to russet formation on the exocarp of the mutant pear. Furthermore, the contents of H2O2, spermidine, spermine, and putrescine and H2O2 localization provided a comprehensive transcriptomic view of russet formation in the mutant pear.
转录组序列中与木栓质、多胺和转录因子相关的差异基因，以及经甲基乙二醛双（脒基腙）（MGBG）处理后，过氧化氢（H₂O₂）、亚精胺、精胺和腐胺的含量发生了显著变化。锈皮形成是一个具有重要商业价值的过程，它通过在梨原果微裂表皮下方形成防水周皮，恢复对经表皮水分流失的控制。已鉴定出一种自发锈皮突变体，即黄绿色的‘砀山酥梨’。为了解多胺在突变型（MT）梨锈皮形成中的作用，在盛花后用甲基乙二醛双（脒基腙）（MGBG）对其处理4周。一周后，筛选野生型（WT）、MT和经MGBG处理的MT梨之间的差异表达基因，用三氯化铈定位过氧化氢（H₂O₂），并测定H₂O₂和多胺的含量。从WT、MT和经MGBG处理的MT转录组中分别产生了57,086,772、61,240,014和67,919,420条成功读取序列，平均单基因长度分别为701、720和735 bp。在‘砀山酥梨’及其突变体文库中筛选了参与多胺代谢和木栓质合成的差异表达基因，发现经MGBG处理后它们的相对表达发生了显著改变，这通过实时PCR得到了证实。鉴定了差异表达转录因子的表达模式，发现其与多胺和木栓质相关基因的表达模式相似。结果表明，多胺代谢过程中产生的H₂O₂可能有助于突变型梨外果皮锈皮的形成。此外，H₂O₂、亚精胺、精胺、腐胺的含量以及H₂O₂定位为突变型梨锈皮形成提供了全面的转录组视角。
