Gibberellin requirement for Arabidopsis seed germination is determined both by testa characteristics and embryonic abscisic acid
Gibberellin requirement for Arabidopsis seed germination is determined both by testa characteristics and embryonic abscisic acid
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DOI：
10.1104/pp.122.2.415
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发表时间：
2000-02-01
期刊：
影响因子：
7.4
通讯作者：
Koornneef, M
中科院分区：
文献类型：
--
作者：
Debeaujon, I;Koornneef, M
施加赤霉素（CA）的要求，以促进休眠和非休眠拟南芥种子发芽的机制进行了分析，使用GA缺陷突变体ga 1，几种种皮色素和结构突变体，和脱落酸（阿坝）缺陷突变体aba 1。种皮突变体，表现出减少种子休眠，不耐GA生物合成抑制剂，如四环素和多效唑，相反，在拟南芥中发现的其他非休眠突变体之前。然而，在抑制剂的存在下或当转移到GA缺陷背景时，种皮突变体对外源GA比野生型更敏感。ga 1 -1突变体的发芽能力可以整体恢复，而无需外源GA的帮助下，通过去除信封或通过转移到一个tt背景（tt 4和ttg 1）的突变。双突变体仍然需要光照和低温打破休眠，这可能表明这两种试剂可以有独立的GA生物合成的影响。阿坝生物合成抑制剂氟草酮在解除野生型和突变体种子休眠方面部分有效。这些结果表明，GAs需要克服的发芽限制所施加的种皮和ABA相关的胚休眠。
The mechanisms imposing a gibberellin (CA) requirement to promote the germination of dormant and non-dormant Arabidopsis seeds were analyzed using the GA-deficient mutant ga1, several seed coat pigmentation and structure mutants, and the abscisic acid (ABA)-deficient mutant aba1. Testa mutants, which exhibit reduced seed dormancy, were not resistant to GA biosynthesis inhibitors such as tetcyclacis and paclobutrazol, contrarily to what was found before for other non-dormant mutants in Arabidopsis. However, testa mutants were more sensitive to exogenous GAs than the wild-types in the presence of the inhibitors or when transferred to a GA-deficient background. The germination capacity of the ga1-1 mutant could be integrally restored, without the help of exogenous GAs, by removing the envelopes or by transferring the mutation to a tt background (tt4 and ttg1). The double mutants still required light and chilling for dormancy breaking, which may indicate that both agents can have an effect independently of GA biosynthesis. The ABA biosynthesis inhibitor norflurazon was partially efficient in releasing the dormancy of wild-type and mutant seeds. These results suggest that GAs are required to overcome the germination constraints imposed both by the seed coat and ABA-related embryo dormancy.