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the plant journal：拟南芥胚乳表达基因ICE1和ZOU作用于种子休眠

已有 3729 次阅读 2019-3-4 12:12 |个人分类:每日摘要|系统分类:论文交流

ICE1 and ZOU determine the depth of primary seed dormancy in Arabidopsis independently of their role in endosperm development

First author: Dana R. MacGregor; Affiliations: John Innes Centre (约翰英纳斯中心): Norwich, UK

Corresponding author: Dana R. MacGregor

Seed dormancy is a widespread and key adaptive trait that is essential for the establishment of soil seed banks and prevention of pre‐harvest sprouting. Herein we demonstrate that the endosperm‐expressed transcription factors ZHOUPI (ZOU) and INDUCER OF CBF EXPRESSION1 (ICE1) play a role in determining the depth of primary dormancy in Arabidopsis. We show that ice1 or zou increases seed dormancy and the double mutant has an additive phenotype. This increased dormancy is associated with increased ABA levels, and can be separated genetically from any role in endosperm maturation because loss of ABA biosynthesis or DELAY OF GERMINATION 1 reverses the dormancy phenotype without affecting the aberrant seed morphology. Consistent with these results, ice1 endosperms had an increased capacity for preventing embryo greening, a phenotype previously associated with an increase in endospermic ABA levels. Although ice1 changes the expression of many genes, including some in ABA biosynthesis, catabolism and/or signalling, only ABA INSENSITIVE 3 is significantly misregulated in ice1 mutants. We also demonstrate that ICE1 binds to and inhibits expression of ABA INSENSITIVE 3. Our data demonstrate that Arabidopsis ICE1 and ZOU determine the depth of primary dormancy during maturation independently of their effect on endosperm development.

种子休眠是一个十分广泛且非常关键的适应性性状，其有利于土壤种子库的建立以及防止种子在收获前发芽。作者在本文中揭示了胚乳表达的转录因子ZOU和ICE1在拟南芥种子初生休眠的深度中发挥作用。ice1或者zou突变体的种子休眠增强，并且ice1 zou双突变体具有加性表型。ice1或者zou突变体种子休眠的增强与ABA水平的增加有关，并且可以与其在胚乳成熟中的作用完全区分开，因为ABA生物合成基因缺陷或者DELAY OF GERMINATION 1能够恢复种子休眠的表型，但不会影响异常的种子形态。此外，ice1的胚乳组织胚胎绿化的能力增强，这种能力之前的研究显示与胚乳中ABA水平的增加相关。尽管ice1改变了很多基因的表达，包括ABA生物合成、代谢及信号通路上的基因，但仅ABA INSENSITIVE 3一个基因在ice1突变体中显著被错误调控了。进一步研究显示ICE1能够结合ABA INSENSITIVE 3，并抑制该基因的表达。本文的研究结果显示ICE1和ZOU通过独立于其在胚乳发育中的作用决定种子的初生休眠深度。