茉莉酸甲酯对橡胶树花药愈伤乳管细胞分化的影响

Effect of Methyl Jasmonate on Laticifer Cell Differentiation of Hevea brasiliensis Anther Calli

橡胶树老化的愈伤组织存在乳管细胞。茉莉酸甲酯(MeJA)与茉莉酸(JA)同属茉莉酸类物质(JAs),但MeJA对橡胶树愈伤乳管细胞分化的效果尚不清楚。系统研究MeJA对橡胶树愈伤乳管细胞分化的效果,结果发现,低浓度的MeJA(0~1 mg/L)对花药愈伤组织的生长影响不明显,而高浓度的MeJA(2~3 mg/L)会抑制愈伤组织生长,且MeJA浓度与愈伤组织生长呈负相关关系。组织化学制片结果显示,低浓度的MeJA能显著提高愈伤乳管细胞发生频率,其中浓度为1 mg/L效果最佳;而高浓度的MeJA则会降低其发生频率。荧光定量PCR结果显示,培养基中添加MeJA后SRPP、REF、CPT等与橡胶生物合成相关的重要基因的表达量在愈伤组织中变化趋势与愈伤乳管细胞发生频率的变化趋势基本一致,进一步证实MeJA能促进愈伤乳管细胞分化。透射电镜观察发现愈伤乳管细胞内含有橡胶粒子、黄色体等细胞器。研究结果对促进橡胶树愈伤组织在乳管分化研究中的应用,以及开发新型橡胶树增产刺激剂,促进橡胶树天然橡胶的生产具有一定意义。

Laticifer cells present in aging calli of Hevea brasiliensis.Methyl jasmonate(MeJA)and jasmonic acid(JA)belong to jasmonates(JAs).However,the effect of MeJA on laticifer cell differentiation of the rubber tree anther calli is unclear.In the present paper,the effect of MeJA on laticifer cell differentiation of anther calli was systematically studied.MeJA added to media in the range of 0‒1 mg/L did not influence the growth of anther calli,while higher concentration of MeJA in media in the range of 2‒3 mg/L severely inhibited callus growth.MeJA concentration in media was nega-tively correlated with callus growth.Histochemical sections showed that low concentration of MeJA in media greatly promoted the differentiation of callus laticifer cells and remarkably increased the occurring frequency,while high con-centration of MeJA in media gravely impeded callus laticifer cell differentiation and strikingly decreased the occurring frequency.Among them,1 mg/L MeJA in media was the optimal concentration to improve the differentiation of laticifer cells in calli.qPCR results showed that when the media were supplemented with MeJA,the change trend of the expres-sion level of genes that was essential in latex biosynthesis,such as small rubber particle protein(SRPP),rubber elonga-tion factor(REF),and cis-prenyl transferase(CPT),was basically consistent with that of the occurring frequency of callus laticifer cells,which further confirmed that MeJA promoted the differentiation of callus laticifer cells.Transmission electron microscopy observation showed that callus laticifer cells contained some specific organelles,such as rub-ber particles and lutoids.The results of this paper are of great significance for promoting the application of rubber tree callus in the study of laticifer differentiation,and for developing rubber tree novel yield-increasing reagents.