PpMADS1和PpMADS2是从‘酥梨’(Pyrus pyrifolia white pear group‘Suli’)休眠芽转录组文库筛选的两个与休眠相关的MADS-box基因序列。为了解序列的特征,对其进行了相关生物信息学分析,并以‘翠冠’和‘圆黄’梨为试材,用实时定量PCR...PpMADS1和PpMADS2是从‘酥梨’(Pyrus pyrifolia white pear group‘Suli’)休眠芽转录组文库筛选的两个与休眠相关的MADS-box基因序列。为了解序列的特征,对其进行了相关生物信息学分析,并以‘翠冠’和‘圆黄’梨为试材,用实时定量PCR技术分析其花芽休眠不同阶段的表达变化。结果表明:两个基因都具有MADS-box家族的特征序列MIKC-基序,PpMADS1和PpMADS2分别与日本梨(P.pyrifolia‘Kosui’)休眠相关的两个MADS-box基因PpMADS13-1和PpMADS13-2聚在一起,且单独聚为一支,与李属植物休眠相关的MADS-box基因关系最近。在两个品种的休眠过程中,PpMADS1和PpMADS2的表达呈现相似的变化趋势,都有一个表达高峰,但‘翠冠’梨PpMADS1和PpMADS2的表达高峰均出现在11月15日,而‘圆黄’梨PpMADS1的表达高峰延后到12月30日,PpMADS2的表达高峰出现在12月15日。两个品种PpMADS1和PpMADS2的表达高峰都出现在内休眠解除之前,随内休眠解除其表达量下调,在生态休眠阶段表达量维持在较低的水平。据此推测PpMADS1和PpMADS2的表达对梨芽内休眠的解除具有调控作用。展开更多
Plants encounter a variety of stresses in natural environments. One-year-old pot-grown trees of pear(Pyrus pyrifolia Nakai cv. Cuiguan and Wonhwang) were exposed to two heat stress regimes. Under constant short-term h...Plants encounter a variety of stresses in natural environments. One-year-old pot-grown trees of pear(Pyrus pyrifolia Nakai cv. Cuiguan and Wonhwang) were exposed to two heat stress regimes. Under constant short-term heat stress, chloroplasts and mitochondria were visibly damaged. Relative chlorophyll content and maximum photochemical efficiency of photosystem II were significantly decreased, which indicated that the leaf photosynthetic capability declined. Under chronic heat stress, mesophyll cell ultrastructure was not obviously damaged, but leaf photosynthetic capability was still restrained. As chronic heat stress was a simulation of the natural environment in summer, further study of the responses under this stress regime was undertaken. Ascorbate peroxidase(APX) activity was increased in ‘Cuiguan', but not in ‘Wonhwang'. Inducible expression of PpAPX genes in the cytoplasm, chloroplasts and peroxisomes was consistent with increased APX activity in ‘Cuiguan', whereas only weak induction of PpAPX genes was observed in ‘Wonhwang'. The isoenzymes cytosolic APX1(cAPX1) and stromal APX(sAPX) were confirmed to be localized in the cytoplasm and chloroplasts, respectively.展开更多
文摘PpMADS1和PpMADS2是从‘酥梨’(Pyrus pyrifolia white pear group‘Suli’)休眠芽转录组文库筛选的两个与休眠相关的MADS-box基因序列。为了解序列的特征,对其进行了相关生物信息学分析,并以‘翠冠’和‘圆黄’梨为试材,用实时定量PCR技术分析其花芽休眠不同阶段的表达变化。结果表明:两个基因都具有MADS-box家族的特征序列MIKC-基序,PpMADS1和PpMADS2分别与日本梨(P.pyrifolia‘Kosui’)休眠相关的两个MADS-box基因PpMADS13-1和PpMADS13-2聚在一起,且单独聚为一支,与李属植物休眠相关的MADS-box基因关系最近。在两个品种的休眠过程中,PpMADS1和PpMADS2的表达呈现相似的变化趋势,都有一个表达高峰,但‘翠冠’梨PpMADS1和PpMADS2的表达高峰均出现在11月15日,而‘圆黄’梨PpMADS1的表达高峰延后到12月30日,PpMADS2的表达高峰出现在12月15日。两个品种PpMADS1和PpMADS2的表达高峰都出现在内休眠解除之前,随内休眠解除其表达量下调,在生态休眠阶段表达量维持在较低的水平。据此推测PpMADS1和PpMADS2的表达对梨芽内休眠的解除具有调控作用。
基金supported by the Earmarked Fund for the Modern Agro-industry Technology Research System,China
文摘Plants encounter a variety of stresses in natural environments. One-year-old pot-grown trees of pear(Pyrus pyrifolia Nakai cv. Cuiguan and Wonhwang) were exposed to two heat stress regimes. Under constant short-term heat stress, chloroplasts and mitochondria were visibly damaged. Relative chlorophyll content and maximum photochemical efficiency of photosystem II were significantly decreased, which indicated that the leaf photosynthetic capability declined. Under chronic heat stress, mesophyll cell ultrastructure was not obviously damaged, but leaf photosynthetic capability was still restrained. As chronic heat stress was a simulation of the natural environment in summer, further study of the responses under this stress regime was undertaken. Ascorbate peroxidase(APX) activity was increased in ‘Cuiguan', but not in ‘Wonhwang'. Inducible expression of PpAPX genes in the cytoplasm, chloroplasts and peroxisomes was consistent with increased APX activity in ‘Cuiguan', whereas only weak induction of PpAPX genes was observed in ‘Wonhwang'. The isoenzymes cytosolic APX1(cAPX1) and stromal APX(sAPX) were confirmed to be localized in the cytoplasm and chloroplasts, respectively.
