植物生長素是一種植物荷爾蒙,，能夠促進植物根系和果實生長,，控制植物發(fā)育的所有階段。例如,，在黑暗的地方大豆可以發(fā)芽,，經(jīng)過光照，便可長出葉片進行光合作用,；倒伏的植物最快情況下經(jīng)過30分鐘便可直立,，這些植物對環(huán)境的應答反應都有生長素的參與。
日本理化學研究所公布,，他們和農(nóng)業(yè)食品產(chǎn)業(yè)技術研究機構以及東京大學組成的聯(lián)合研究小組于世界上首次發(fā)現(xiàn)了阻礙植物“生長素”生物合成的抑制劑的存在,。
鑒于生長素在植物成長控制中具有重要作用，其在農(nóng)業(yè)栽培領域具有廣泛的應用前景,，但與其他植物荷爾蒙相比,，人們對它的不了解尚不充分。生長素在植物體內(nèi)含量甚微,，其生物合成路徑復雜,，化學性質不穩(wěn)定,，設計生物合成抑制劑也極其困難,。諸多問題導致了生長素的基礎研究和相關應用滯后，目前僅限于在農(nóng)業(yè)除草劑和植物調節(jié)劑中應用具有生長素活性的生長素親體,，但尚無控制生長素作用的有效藥劑和技術,。
該聯(lián)合研究小組對模型植物擬南芥的遺傳發(fā)現(xiàn)類型進行了大規(guī)模的破解，并對獲得的數(shù)據(jù)進行分析,，以尋找可控制植物荷爾蒙作用藥劑,，結果發(fā)現(xiàn)了妨礙生長素生物合成的候補化合物AVG和AOPP。研究小組通過對這些化合物的功能進行深入研究后,，確認了阻礙生長素生物合成的物質,。該研究成果將發(fā)表在4月出版的《植物和細胞生理學》雜志,。
研究人員表示，利用植物生長素生物合成抑制劑,，可培育出以前無法實現(xiàn)的生長素缺乏狀態(tài)的植物,，這將為研究生長素的機能及其復雜的生物合成路徑提供思路。目前植物生長素的研究尚限定于模型植物,，未來可將研究范圍擴展至農(nóng)作物等高實用性作物,，有朝一日開發(fā)出控制植物生長的新藥和技術，開拓出嶄新的農(nóng)業(yè)栽培技術,，將對促進農(nóng)業(yè)生產(chǎn)起到關鍵作用,。(生物谷Bioon.com)
生物谷推薦原文出處：
Plant and Cell Physiology doi:10.1093/pcp/pcq032
Auxin-biosynthesis inhibitors, identified by genomics-based approach, provide insights into auxin biosynthesis.
Kazuo Soeno1,4,, Hideki Goda1,, Takahiro Ishii1, Takehiko Ogura1, Tomoe Tachikawa1, Eriko Sasaki1,2, Shigeo Yoshida1, Shozo Fujioka3, Tadao Asami2 and Yukihisa Shimada1,2,*
1 RIKEN Plant Science Center, Suehirocho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
2 Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan
3 RIKEN Advanced Science Institute, Wako, Saitama 351-0198, Japan
4 National Agricultural Research Center for Western Region (WeNARC), National Agriculture and Food Research Organization (NARO), Senyu, Zentsuji, Kagawa 765-8508, Japan
Despite its importance in plant growth and development, the auxin biosynthetic pathway has remained elusive. In this study, we analyzed hormone series transcriptome data from AtGenExpress in Arabidopsis and found that aminoethoxyvinylglycine (AVG) had the strongest anti-auxin activity. We also identified other effective compounds such as L-aminooxyphenylpropionic acid (AOPP) through additional screening. These inhibitors shared characteristics in that they inhibited pyridoxal enzymes and/or aminotransferases. They reduced endogenous indole-3-acetic acid (IAA) levels in both monocots and dicots. L-AOPP inhibited root development of Arabidopsis in main root elongation, gravitropism, root skewing, and root hair formation. This inhibition was generally recovered after exogenous IAA treatment, and the recovery was almost completely to the level of non-inhibited seedlings. The compounds inhibited conversion from Trp to indole-3-pyruvic acid in enzyme extracts from Arabidopsis and wheat. Our data collectively suggest that the inhibitors directly blocked auxin biosynthesis, and that the major target site was Trp aminotransferase. This enzyme likely makes up one of the major biosynthesis pathways conserved among higher plants. Each inhibitor, however, demonstrated a different action spectrum in shoot and root of rice and tomato, indicating diversity in biosynthesis pathways between organs and species. Our results provide novel insights into auxin biosynthesis and action, and uncover structural characteristics of auxin biosynthesis inhibitors.
