Identification of 6-epi-heliolactone as a biosynthetic precursor of avenaol in Avena strigosa
Identification of 6-epi-heliolactone as a biosynthetic precursor of avenaol in Avena strigosa
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DOI：
10.1093/bbb/zbac069
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发表时间：
2022-06-09
影响因子：
1.6
通讯作者：
Sugimoto, Yukihiro
中科院分区：
文献类型：
--
作者：
Moriyama, Daisuke;Wakabayashi, Takatoshi;Sugimoto, Yukihiro
独脚金内酯（Strigolactones，SL）是根际信号分子和植物激素，可调节植物的茎结构，根据其结构可分为典型SL和非典型SL。Avenaol是黑燕麦（Avena strigosa）根分泌物中发现的非典型SL，具有特征性的双环[4.1.0]庚烷骨架。阐明这种特殊结构的生物合成机制是进一步理解非典型SL结构多样性的挑战。在这项研究中，一个新的非经典SL，6-epi-heliolactone黑燕麦根分泌物中鉴定。饲养实验表明，6-表-向日葵内酯是一种生物合成中间体，它介于己酸甲酯和燕麦醇之间。抑制剂实验提出2-酮戊二酸依赖性双加氧酶参与6-表-向日葵内酯转化为燕麦醇。这些结果为深入了解非经典SL的立体化学多样性提供了新的视角，并为探索燕麦醇的生物合成途径提供了基础。
Strigolactones (SLs), which are known as rhizosphere signaling molecules and plant hormones regulating shoot architecture, are classified into 2 distinct groups, canonical and noncanonical SLs, based on their structures. Avenaol, a noncanonical SL found in the root exudates of black oat (Avena strigosa), has a characteristic bicyclo[4.1.0]heptane skeleton. Elucidating the biosynthetic mechanism of this peculiar structure is a challenge for further understanding of the structural diversification of noncanonical SLs. In this study, a novel noncanonical SL, 6-epi-heliolactone in black oat root exudates was identified. Feeding experiments showed that 6-epi-heliolactone was a biosynthetic intermediate between methyl carlactonoate and avenaol. Inhibitor experiments proposed the involvement of 2-oxoglutarate-dependent dioxygenase in converting 6-epi-heliolactone to avenaol. These results provide new insights into the stereochemistry diversity of noncanonical SLs and a basis to explore the biosynthetic pathway causing avenaol.