Zhang Mingcai, Duan Liusheng, Tian Xiaoli, He Zhongpei, Li Jianmin, Wang Baomin, Li Zhaohu
State Key Laboratory of Plant Physiology and Biochemistry, Department of Agronomy, Centre for Crop Chemical Control, College of Agronomy and Biotechnology, China Agricultural University, 2#, Yuanmingyuan Xilu, Haidian District, Beijing, 100094, PR China.
J Plant Physiol. 2007 Jun;164(6):709-17. doi: 10.1016/j.jplph.2006.04.008.
This study investigated whether uniconazole confers drought tolerance to soybean and if such tolerance is correlated with changes in photosynthesis, hormones and antioxidant system of leaves. Soybean plants were foliar treated with uniconazole at 50 mg L-1 at the beginning of bloom and then exposed to water deficit stress at pod initiation for 7 d. Uniconazole promoted biomass accumulation and seed yield under both water conditions. Plants treated with uniconazole showed higher leaf water potential only in water-stressed condition. Water stress decreased the chlorophyll content and photosynthetic rate, but those of uniconazole-treated plants were higher than the stressed control. Uniconazole increased the maximum quantum yield of photosystemand ribulose-1,5-bisphosphate carboxylase/oxygenase activity of water-stressed plants. Water stress decreased partitioning of assimilated 14C from labeled leaf to the other parts of the plant. In contrast, uniconazole enhanced translocation of assimilated 14C from labeled leaves to the other parts, except stems, regardless of water treatment. Uniconazole-treated plants contained less GA3, GA4 and ABA under well-watered condition than untreated plants, while the IAA and zeatin levels were increased substantially under both water conditions, and ABA concentration was also increased under water stressed condition. Under water-stressed conditions, uniconazole increased the content of proline and soluble sugars, and the activities of superoxide dismutase and peroxidase in soybean leaves but not the malondialdehyde content or electrical conductivity. These results suggest that uniconazole-induced tolerance to water deficit stress in soybean was related to the changes of photosynthesis, hormones and antioxidant system of leaves.
本研究调查了烯效唑是否能赋予大豆耐旱性，以及这种耐受性是否与叶片光合作用、激素和抗氧化系统的变化相关。在开花初期，用50 mg L-1的烯效唑对大豆植株进行叶面处理，然后在结荚初期使其遭受7天的水分亏缺胁迫。在两种水分条件下，烯效唑均促进了生物量积累和种子产量。仅在水分胁迫条件下，用烯效唑处理的植株叶片水势更高。水分胁迫降低了叶绿素含量和光合速率，但烯效唑处理植株的叶绿素含量和光合速率高于胁迫对照。烯效唑提高了水分胁迫植株的光系统最大量子产量和核酮糖-1,5-二磷酸羧化酶/加氧酶活性。水分胁迫降低了标记叶片中同化14C向植株其他部位的分配。相比之下，无论水分处理如何，烯效唑均增强了标记叶片中同化14C向除茎以外的其他部位的转运。在水分充足条件下，烯效唑处理的植株比未处理植株含有更少的GA3、GA4和ABA，而在两种水分条件下，IAA和玉米素水平均大幅增加，在水分胁迫条件下ABA浓度也增加。在水分胁迫条件下，烯效唑增加了大豆叶片中脯氨酸和可溶性糖的含量以及超氧化物歧化酶和过氧化物酶的活性，但未增加丙二醛含量或电导率。这些结果表明，烯效唑诱导的大豆对水分亏缺胁迫的耐受性与叶片光合作用、激素和抗氧化系统的变化有关。
