油菜素類固醇

油菜素類固醇（Brassinosteroids，BRS）又被稱為芸苔素內酯（brassinolides）或是油菜內酯。以化學結構來說屬於固醇類物質是一類多羥基的類固醇，已被視為第六類植物激素。

芸苔素（brassinolides）一開始的研究集中在十字花科蔬菜，它的命名也是來自於十字花科的屬名（brassica）。^[1]^[2]

芸苔素內酯在植物體內扮演著促進植體成熟，開花結果，對抗逆境^[3]^[4]等角色。它會和生長素、細胞分裂素、激勃素等促進生長的賀爾蒙產生加成作用，擴大影響的效應，一般來說在農業上作為增加產量和開花數量的生長調節劑。

在農業上主要有下列的功效：

参考文献

^ Grove, M.D.; Spencer, G.F.; Rohwedder, W.K.; Mandava, N.; Worley, J.F.; Warthen, J.D.; Ste; Flippen-Anderson, J.L.; Cook, J.C.; et al. Brassins: a new family of plant hormones from rape pollen. Nature. 1979, 225 (5237): 1065–66. Bibcode:1970Natur.225.1065M. PMID 16056912. doi:10.1038/2251065a0.
^ Grove, Michael D.; Spencer, Gayland F.; Rohwedder, William K.; Mandava, Nagabhushanam; Worley, Joseph F.; Warthen, J. David; Steffens, George L.; Flippen-Anderson, Judith L.; Cook, J. Carter. Brassinolide, a plant growth-promoting steroid isolated from Brassica napus pollen. Nature. 1979, 281 (5728): 216–217. Bibcode:1979Natur.281..216G. doi:10.1038/281216a0.
^ ^3.0 ^3.1 ^3.2 Sharma, P.; Bhardwaj, R. Effects of 24-Epibrassinolide on growth and metal uptake in "Brassica juncea" L. under copper metal stress. Acta Physiologiae Plantarum. 2007, 29 (3): 259–263. doi:10.1007/s11738-007-0032-7.
^ ^4.0 ^4.1 ^4.2 Sharma, P; Bhardwaj, R; Arora, HK; Arora, N; Kumar, A. Effects of 28-homobrassinolide on nickel uptake, protein content and antioxidative defence system in "Brassica juncea. Biol. Plant. 2008, 52 (4): 767–770. doi:10.1007/s10535-008-0149-6.
^ ^5.0 ^5.1 Xiao Jian, Xia; Zhang, Y; Wu, JX; Wang, JT; Zhou, YH; Shi, K; Yu, YL; Yu, JQ. Brassinosteroids Promote Metabolism of Pesticides in Cucumber. J. Agric. Food Chem. 2009, 57 (18): 8406–8413. PMID 19694443. doi:10.1021/jf901915a.