Variation in the phenotypic features and transcripts of thermo-sensitive leaf-color mutant induced by carbon ion beam in Green wandering jew (Tradescantia fluminensis)
Variation in the phenotypic features and transcripts of thermo-sensitive leaf-color mutant induced by carbon ion beam in Green wandering jew (Tradescantia fluminensis)
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DOI：
10.1016/j.scienta.2016.11.001
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发表时间：
2016-12
影响因子：
4.3
通讯作者：
Ruiyuan Liu;Xicun Dong;Wenting Gu;Lixia Yu;W. Jin;Y. Qu;Feng Zhang;Wen‐jian Li
中科院分区：
文献类型：
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作者：
Ruiyuan Liu;Xicun Dong;Wenting Gu;Lixia Yu;W. Jin;Y. Qu;Feng Zhang;Wen‐jian Li
叶色突变体是研究植物生理过程的理想材料。在此，通过碳离子辐照分离到一个绿色漂泊犹太人的热敏叶色突变体，命名为asmt。突变株幼叶颜色对温度变化较为敏感，而野生型幼叶在低温条件下(6℃~20℃)仍保持绿色。为了阐明突变体叶片在常温(25℃)和低温(7℃)条件下的色素形成特征，我们通过四个独立的实验研究了这一现象的超微结构、色素组成、分子机制和花青素积累。结果表明，在25℃时，突变体的叶绿体形态和分布出现异常，在低温条件下(7℃)，突变体叶片中的叶绿体转化为白质体。温度变化影响了突变体叶片的转色速率、叶绿素和花青素含量。分子分析表明，在7℃时，突变体叶片中的所有花青素生物合成基因和调控基因均呈结构性上调，除PAL、CHS、ANS外，其余基因在25℃时的表达水平与野生型相似。对突变体和野生型叶片中花色苷的高效液相色谱分析表明，除在室温(25℃)条件下未检测到天花粉外，突变体和野生型叶片中花青素的含量显著低于低温条件下(7℃)。高效液相色谱图谱还表明，在7℃时，突变叶片中的黄酮醇含量最高。以上结果表明，叶色突变体的超微结构、色素组成、转录量和花青素积累与温度变化密切相关。这些发现将为更好地理解不同温度条件下漂泊的犹太人突变体叶片的色素变化机制。
Leaf color mutants are ideal materials for studying physiological processes in plants. Here, a thermos-sensitive leaf-color mutant of Green wandering jew was isolated after carbon ions irradiation, which was designated asmt. The color of young mutant leaves was more sensitive to variations of temperature, however, the young leaves of wild type remained green under low – temperature conditions (6 °C-20 °C). To elucidate the characteristics of pigmentation in mutant leaves under room temperature conditions (25 °C) and low – temperature conditions (7 °C), the ultra-structural, pigment composition, molecular mechanisms and anthocyanin accumulation involved in this phenomenon have been investigated in four independent experiments. The results showed that chloroplasts of mutants exhibited abnormal morphology and distribution at 25 °C, and under low – temperature conditions(7 °C), the chloroplasts converted into leucoplast in leaves on mutants. Temperature change affected the rate of color transition, chlorophyll and anthocyanin concentrations in leaves on mutants. Molecular analysis indicated that all the anthocyanin biosynthetic genes and regulatory genes were constitutively up-regulated in mutant leaves at 7 °C. The other anthocyanin biosynthesis and regulatory genes showed similar expression levels between mutant and wild type exceptPAL,CHS,ANSwere up-regulated at 25 °C. HPLC analysis of anthocyanins in mutant and wild type leaves revealed that the contents of cyanidin, petunidin and delphinidin were significantly lower than those of under low-temperature conditions (7 °C) except pelargonidin was not detected in mutant leaves under room – temperature conditions(25 °C). The HPLC profile also indicated the highest levels of flavonols in mutant leaves at 7 °C significantly. Overall, above results indicated a close similarity among ultra-structures, pigment compositions, transcript amount and anthocyanin accumulation were tightly associated with temperature variation in leaves of leaf color mutant. These findings would provide better understanding of the mechanism of pigmentation changes in mutant leaves under different temperature conditions in Wandering jew.