岩石壁上爬山虎茎产生不定根时木质部中激素与结构变化研究

Changes of Phytohormone and Structure in Xylem During Adventitious Root Production from the Stem of Parthenocissus tricuspidata Planch on the Rock Wall

为探索岩石壁上爬山虎木质生长茎自发产生不定根这一科学问题,以其3类茎为试材,用酶联免疫法检测茎木质部中激素含量及施入外源激素引发茎内产生不定根原基并发育时的激素水平。结果表明一年生爬山虎茎中不定根原基属于内起源。各试材木质部中生长素(IAA)以鲜重计最高为11.486μg/g,最低为6.255μg/g。细胞分裂素(CTK)以鲜重计最高为232.295 ng/g,最低为150.235 ng/g;但施入外源激素的一年生爬山虎茎内产生不定根原基时CTK最高为232.295 ng/g。茉莉酸(JA)含量远低于植物营养器官按鲜重计10~100 ng/g范围,但生根茎内浓度远高于不生根茎。而茉莉酸甲酯(Me-JA)在各试材木质部内含量极微,但生根茎内浓度远高于不生根茎。爬山虎生根茎木质部内IAA/CTK达到27~76,生根茎木质部内激素浓度远高于未生根茎,且外施激素使茎产生不定根时激素浓度均大幅升高,表明其茎自发产生不定根需要多种内源激素协同作用。

To explore the spontaneously produced adventitious roots in the woody stems of Parthenocissus tricuspidata Planch on the rock wall,three kinds of stems were used as test materials.The hormone content in the xylem of the stem and the hormone level during the formation and development of adventitious root primordium induced by exogenous hormone were detected by enzyme-linked immunosorbent assay(Elisa).The results showed that the adventitious root primordium in the stem of annual Parthenocissus tricuspidata Planch belonged to internal origin.In the xylem of each test wood,the highest auxin(IAA)was 11.486μg/g and the lowest was 6.255μg/g counted on fresh weight.The highest of cytokinin(CTK)was 232.295 ng/g and the lowest was 150.235 ng/g counted on fresh weight,but the highest CTK was 232.295 ng/g when the adventitious root primordium was produced in the stem of 1-year-old Parthenocissus tricuspidata Planch treated with the exogenous hormone.The content of jasmonic acid(JA)was much lower than the 10-100 ng/g range of plant vegetative organs according to fresh weight,but the concentration in the rooting stem was much higher than that in the non-rooting stem.However,the content of methyl jasmonate(Me-JA)in the xylem of each test wood was very low,but the concentration in the rooting stem was much higher than that in the non-rooting stem.The IAA/CTK in the xylem of Rhizoma Parthenocissus tricuspidata Planch reached 27-76,and the concentration of hormone in the xylem of the rooting stem was much higher than that of the non-rooting stem,and the hormone concentration increased significantly when the stem produced adventitious root,which indicated that the spontaneous production of the stem adventitious root required the synergistic action of many kinds of endogenous hormones.