A chemical biology approach reveals an opposite action between thermospermine and auxin in xylem development in Arabidopsis thaliana.
A chemical biology approach reveals an opposite action between thermospermine and auxin in xylem development in Arabidopsis thaliana.
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化学生物学方法揭示了拟南芥木质部发育中热精胺和生长素之间的相反作用。
DOI：
10.1093/pcp/pcs017
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发表时间：
2012
影响因子：
4.9
通讯作者：
H. Motose
中科院分区：
文献类型：
--
作者：
Kaori Yoshimoto;Y. Noutoshi;Ken;K. Shirasu;Taku Takahashi;H. Motose
热精胺是精胺的一种结构异构体，通过aculis5 （ACL5）的作用产生，抑制拟南芥木质部分化。为了阐明热精胺功能的分子基础，我们筛选了能够调节acl5突变体木质部分化的化合物，该突变体缺乏热精胺，并表现出与木质部血管过度增生相关的严重矮化表型。我们发现合成生长素的异辛酯2,4- d显著促进了acl5幼苗木质部导管的分化。2,4- d、2,4- d类似物和IAA类似物，包括4-氯IAA （4-Cl-IAA）和IAA乙酯也能促进木质部导管的形成，而IAA对木质部分化的影响很小或不明显。这些生长素类似物的作用仅在acl5突变体中观察到，而在野生型中没有，并且被抗生长素、对氯苯氧异丁酸（PCIB）和α-（苯基乙基-2- 1）- iaa （PEO-IAA）和热精胺抑制。此外，acaulis51-d （SAC51 -d）突变抑制因子在缺乏热精胺的情况下导致SAC51过表达，抑制acl5的矮化表型，也抑制了生长素类似物在acl5中的作用。这些结果表明，促进木质部分化的生长素信号通常受到sac51介导的热精胺信号的限制，但在缺乏热精胺的情况下，外源生长素类似物可以持续刺激生长素信号。热精胺和生长素之间的相反作用可能微调木质部分化的时间和空间格局。
Thermospermine, a structural isomer of spermine, is produced through the action of ACAULIS5 (ACL5) and suppresses xylem differentiation in Arabidopsis thaliana. To elucidate the molecular basis of the function of thermospermine, we screened chemical libraries for compounds that can modulate xylem differentiation in the acl5 mutant, which is deficient in thermospermine and shows a severe dwarf phenotype associated with excessive proliferation of xylem vessels. We found that the isooctyl ester of a synthetic auxin, 2,4-D, remarkably enhanced xylem vessel differentiation in acl5 seedlings. 2,4-D, 2,4-D analogs and IAA analogs, including 4-chloro IAA (4-Cl-IAA) and IAA ethyl ester, also enhanced xylem vessel formation, while IAA alone had little or no obvious effect on xylem differentiation. These effects of auxin analogs were observed only in the acl5 mutant but not in the wild type, and were suppressed by the anti-auxin, p-chlorophenoxyisobutyric acid (PCIB) and α-(phenyl ethyl-2-one)-IAA (PEO-IAA), and also by thermospermine. Furthermore, the suppressor of acaulis51-d (sac51-d) mutation, which causes SAC51 overexpression in the absence of thermospermine and suppresses the dwarf phenotype of acl5, also suppressed the effect of auxin analogs in acl5. These results suggest that the auxin signaling that promotes xylem differentiation is normally limited by SAC51-mediated thermospermine signaling but can be continually stimulated by exogenous auxin analogs in the absence of thermospermine. The opposite action between thermospermine and auxin may fine-tune the timing and spatial pattern of xylem differentiation.
DOI：
10.1073/pnas.0806324105
发表时间：
2008-09-30
影响因子：
11.1
作者：
Savaldi-Goldstein, Sigal;Baiga, Thomas J.;Chory, Joanne
通讯作者：
Chory, Joanne
影响因子：
4
作者：
Hayashi, Ken-ichiro;Neve, Joshua;Nozaki, Hiroshi
通讯作者：
Nozaki, Hiroshi