Alterations in Seed Development Gene Expression Affect Size and Oil Content of Arabidopsis Seeds
Alterations in Seed Development Gene Expression Affect Size and Oil Content of Arabidopsis Seeds
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DOI：
10.1104/pp.113.226761
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发表时间：
2013-10-01
期刊：
影响因子：
7.4
通讯作者：
Doermann, Peter
中科院分区：
文献类型：
--
作者：
Fatihi, Abdelhak;Zbierzak, Anna Maria;Doermann, Peter
拟南芥种子胚乳的发育受多梳复合体的控制，其中多梳复合体包括不依赖受精作用的胚乳（FIE）。多梳群复合物调节下游因子，如：G. Pheres 1（PHE 1），通过基因组印记。在杂合的fie突变体中，胚乳在携带母本fie等位基因的胚珠中发育而不受精，最终导致败育。另一种胚乳发育途径依赖于MINISEED 3（WRKY 10转录因子）和HAIKU 2（富含亮氨酸的重复激酶）。虽然种子发育基因在胚和胚乳建立中的作用已被详细研究，但它们对代谢和油积累的影响仍不清楚。对这四个种子发育基因的突变体和过表达植株中的油、蛋白质和蔗糖积累的分析表明：（1）携带母本fie等位基因的种子积累低油，三酰甘油分子种类的组成改变;（2）phe 1、mini3和iku 2的纯合突变种子，它们较小，积累较少的油和略微较少的蛋白质和淀粉，（3）FIE、PHE 1和MINI 3的胚特异性过表达对种子大小和重量没有影响，也不影响油、蛋白质或蔗糖含量;（4）IKU 2的过表达导致种子的大小和重量增加，并且过表达的IKU 2种子的含油量增加35%。因此，IKU 2的过表达代表了一种新的策略，在种子中的油含量的遗传操作。
Seed endosperm development in Arabidopsis (Arabidopsis thaliana) is under control of the polycomb group complex, which includes Fertilization Independent Endosperm (FIE). The polycomb group complex regulates downstream factors, e. g. Pheres1 (PHE1), by genomic imprinting. In heterozygous fie mutants, an endosperm develops in ovules carrying a maternal fie allele without fertilization, finally leading to abortion. Another endosperm development pathway depends on MINISEED3 (a WRKY10 transcription factor) and HAIKU2 (a leucine-rich repeat kinase). While the role of seed development genes in the embryo and endosperm establishment has been studied in detail, their impact on metabolism and oil accumulation remained unclear. Analysis of oil, protein, and sucrose accumulation in mutants and overexpression plants of the four seed development genes revealed that (1) seeds carrying a maternal fie allele accumulate low oil with an altered composition of triacylglycerol molecular species; (2) homozygous mutant seeds of phe1, mini3, and iku2, which are smaller, accumulate less oil and slightly less protein, and starch, which accumulates early during seed development, remains elevated in mutant seeds; (3) embryo-specific overexpression of FIE, PHE1, and MINI3 has no influence on seed size and weight, nor on oil, protein, or sucrose content; and (4) overexpression of IKU2 results in seeds with increased size and weight, and oil content of overexpressed IKU2 seeds is increased by 35%. Thus, IKU2 overexpression represents a novel strategy for the genetic manipulation of the oil content in seeds.