《植物生理学报》 2013, 49(5): 452-456

甜瓜属正反交杂种叶绿素生物合成与代谢研究

陈友根^1,2, 崔利¹, 陈劲枫^1,*

1南京农业大学园艺学院, 作物遗传与种质创新国家重点实验室, 南京210095; 2安徽农业大学园艺学院, 合肥230036

通信作者：陈劲枫；E-mail: jfchen@njau.edu.cn；Tel: 13951722067

摘　要：

对甜瓜属野生黄瓜(Cucumis hystrix Chakr., 2n=24, 简称HH)和栽培黄瓜‘北京截头’ (Cucumis sativus cv. Beijingjietou, 2n=14, 简称CC)的正反交杂种(正交: 野生黄瓜×栽培黄瓜‘北京截头’, HC; 反交: 栽培黄瓜‘北京截头’×野生黄瓜, CH)及亲本的叶绿素含量、叶绿素酶活性和叶绿素合成前体物质含量进行了测定, 以判断甜瓜属正反交杂种发生黄叶新表型变异的可能原因。结果显示, 正反交杂种叶绿素a (Chl a)、叶绿素b (Chl b)、总叶绿素含量均明显降低。正反交杂种叶绿素酶活性虽有升高, 但与双亲差异不显著。叶绿素合成中间产物分析结果显示, 正交杂种(HC)从δ-氨基乙酰丙酸(ALA)到Mg-原卟啉 IX (Mg-Proto IX)过程的物质含量与双亲差异不显著, 但原脱植基叶绿素酸酯(Pchlide)含量明显增加, Chl a含量降低,可知其叶绿素合成受阻于Pchlide转化为Chl a过程; 反交杂种(CH)中ALA和胆色素原(PBG)含量显著增加, 但尿卟啉原(UrogenIII)含量显著降低, 随后的物质含量均有所减少, 可知其叶绿素合成受阻于PBG转化为Urogen III过程。本研究揭示了甜瓜属正反交杂种黄叶新表型产生机制不同, 进一步说明了甜瓜属种间正反交存在差异。

关键词：甜瓜属; 正反交杂种; 叶绿素含量; 叶绿素酶活性; 叶绿素合成前体

收稿：2013-04-02   修定：2013-04-15

资助：国家973计划(2009CB119001-01)和国家自然科学基金(30830079)。

Chlorophyll Biosynthesis and Metabolism Analyses of Reciprocal Interspecific Hybrid between Cucumis hystrix and C. sativus

CHEN You-Gen^1,2, CUI Li¹, CHEN Jin-Feng^1,*

¹State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; ²College of Horticulture, Anhui Agricultural University, Hefei 230036, China

Corresponding author: CHEN Jin-Feng; E-mail: jfchen@njau.edu.cn; Tel: 13951722067

Abstract:

The reciprocal interspecific hybrids between Cucumis hystrix and C. sativus were used to analyze chlorophyll biosynthesis and metabolism by measuring their chlorophyll (Chl) contents, chlorophyllase (Chlase) activities and chlorophyll biosynthesis precursors’ contents in order to reveal the mechanisms of yellow leaves involved. The results showed that the contents of Chl a, Chl b and total chlorophyll in the leaves of HC and CH were significantly lower than those of their parents in the experiment. Nevertheless, the Chlase activities of HC and CH were the nearly comparable to their parents. The content of protochlorophyllide (Pchlide) in HC accu-mulated distinctly, whereas the content of Chl a decreased. The result suggested that the biosynthesis of Chl in HC was blocked at the step of converting Pchlide to Chl a. The content of δ-aminolevulinic acid (ALA) and porphobilinogen (PBG) in CH promoted rapidly, yet uroporphyrinogen (Urogen III) content reduced remark-ably, and the contents of coproporphyrinogen III, protoporphyrin IX, Mg-protoporphyrin IX and protochloro-phyllide were all decreased accordingly. The result displayed that the biosynthesis of Chl in CH was blocked at the step of converting PBG to Urogen III. Simultaneously, we discovered the novel phenotypes of yellow leaves in HC and CH were induced by different mechanism, which further confirmed the reciprocal differences in the interspecific hybridization between C. hystrix and C. sativus.

Key words: Cucumis; reciprocal hybrid; chlorophyll content; Chlase activity; chlorophyll biosynthetic precursors