Apomixis has high value in fruit crop propagation and breeding applications,particularly for the transgenerational fixation of heterosis.In this study,we found that flowers of the triploid Malus cultivar'Royalty&#...Apomixis has high value in fruit crop propagation and breeding applications,particularly for the transgenerational fixation of heterosis.In this study,we found that flowers of the triploid Malus cultivar'Royalty'that were bagged after emasculation(EB)and pollinated with pollen from the diploid cultivar'Flame'(EFB)produced high fruit set and increased seed numbers per fruit.The offspring exhibited superior growth vigour compared to those of the diploid sister cultivar'Flame'.The fruit setting rate for'Royalty'EFB was 98.44%,which was much higher than the fruit setting rate for'Royalty'BA(Bagging without emasculation)at 19.7%.The fruit setting rate for'Royalty'EB was 47.46%compared to 19.7%for'Royalty'BA.Furthermore,offspring derived from either'Royalty'EB or EFB exhibited superior growth vigour compared to those of the diploid'Flame'.These results suggested that'Royalty'exhibits facultative apomixis and has strong sexual reproductive ability under the stimulation of foreign pollen.Additionally,'Royalty'anthers did not dehisce after flowering and had malformed pollen grains and a low pollen germination rate.Therefore,we proposed that dysplasia of the male organ could be an important driver factor of apomixis in'Royalty'.Our study provides new insight into the mechanism of apomixis in Malus crabapples.展开更多
Temperature changes affect apple development and production.Phenylpropanoid metabolism and hormone signaling play a crucial role in regulating apple growth and development in response to temperature changes.Here,we fo...Temperature changes affect apple development and production.Phenylpropanoid metabolism and hormone signaling play a crucial role in regulating apple growth and development in response to temperature changes.Here,we found that McMYB4 is induced by treatment at 28℃ and 18℃,and McMYB4 overexpression results in flavonol and lignin accumulation in apple leaves.Yeast one-hybrid(Y1H)assays and electrophoretic mobility shift assays(EMSAs)further revealed that McMYB4 targets the promoters of the flavonol biosynthesis genes CHS and FLS and the lignin biosynthesis genes CAD and F5H.McMYB4 expression resulted in higher levels of flavonol and lignin biosynthesis in apple during growth at 28℃ and 18℃ than during growth at 23℃.At 28℃ and 18℃,McMYB4 also binds to the AUX/ARF and BRI/BIN promoters to activate gene expression,resulting in acceleration of the auxin and brassinolide signaling pathways.Taken together,our results demonstrate that McMYB4 promotes flavonol biosynthesis and brassinolide signaling,which decreases ROS contents to improve plant resistance and promotes lignin biosynthesis and auxin signaling to regulate plant growth.This study suggests that McMYB4 participates in the abiotic resistance and growth of apple in response to temperature changes by regulating phenylpropanoid metabolism and hormone signaling.展开更多
Adult stem cells or progenitors are essential for maintaining the normal structure and function of adult tissues （i.e., ho- meostasis）. One of the best examples is the adult intestinal epithelium which is constantly...Adult stem cells or progenitors are essential for maintaining the normal structure and function of adult tissues （i.e., ho- meostasis）. One of the best examples is the adult intestinal epithelium which is constantly renewed by the progeny of intestinal stem cells （ISCs）. The proliferation and differentiation of adult stem cells must be tightly controlled in order to maintain resident tissue homeostasis. Mis-regulation of stem cell proliferation and differentiation leads to depletion or excessive proliferation of stem cells, eventually resulting in severe diseases such as cancer （Radtke and Clevers, 2005; Morrison and Spradling, 2008）. Understanding the detailed regulatory mechanisms of stem cell proliferation and differ- entiation will shed insights into the causes of related human diseases.展开更多
基金supported by grants from the National Natural Science Foundation of China(31901997,31772263,31872081)the General Project of the Scientific Research Program of the Beijing Municipal Commission of Education(KM202010020013)+2 种基金the Opening Project of Beijing Key Laboratory of New Technique in Agricultural Application(NYYYXJS201704)the National Key Project of Research and Development Plan(2016YFD0201116)the Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(CEFFPXM2019_014207_000032).
文摘Apomixis has high value in fruit crop propagation and breeding applications,particularly for the transgenerational fixation of heterosis.In this study,we found that flowers of the triploid Malus cultivar'Royalty'that were bagged after emasculation(EB)and pollinated with pollen from the diploid cultivar'Flame'(EFB)produced high fruit set and increased seed numbers per fruit.The offspring exhibited superior growth vigour compared to those of the diploid sister cultivar'Flame'.The fruit setting rate for'Royalty'EFB was 98.44%,which was much higher than the fruit setting rate for'Royalty'BA(Bagging without emasculation)at 19.7%.The fruit setting rate for'Royalty'EB was 47.46%compared to 19.7%for'Royalty'BA.Furthermore,offspring derived from either'Royalty'EB or EFB exhibited superior growth vigour compared to those of the diploid'Flame'.These results suggested that'Royalty'exhibits facultative apomixis and has strong sexual reproductive ability under the stimulation of foreign pollen.Additionally,'Royalty'anthers did not dehisce after flowering and had malformed pollen grains and a low pollen germination rate.Therefore,we proposed that dysplasia of the male organ could be an important driver factor of apomixis in'Royalty'.Our study provides new insight into the mechanism of apomixis in Malus crabapples.
基金This research was funded by the National Natural Science Foundation of China(31772263,31872081)the Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(CEFF-PXM2019_014207_000032)+1 种基金the Scientific Research Improvement Project of Beijing University of Agriculture(GZL2014003)the Agricultural Science and Technology Project of Beijing Municipal Commission of Rural Affairs(No.20180202).
文摘Temperature changes affect apple development and production.Phenylpropanoid metabolism and hormone signaling play a crucial role in regulating apple growth and development in response to temperature changes.Here,we found that McMYB4 is induced by treatment at 28℃ and 18℃,and McMYB4 overexpression results in flavonol and lignin accumulation in apple leaves.Yeast one-hybrid(Y1H)assays and electrophoretic mobility shift assays(EMSAs)further revealed that McMYB4 targets the promoters of the flavonol biosynthesis genes CHS and FLS and the lignin biosynthesis genes CAD and F5H.McMYB4 expression resulted in higher levels of flavonol and lignin biosynthesis in apple during growth at 28℃ and 18℃ than during growth at 23℃.At 28℃ and 18℃,McMYB4 also binds to the AUX/ARF and BRI/BIN promoters to activate gene expression,resulting in acceleration of the auxin and brassinolide signaling pathways.Taken together,our results demonstrate that McMYB4 promotes flavonol biosynthesis and brassinolide signaling,which decreases ROS contents to improve plant resistance and promotes lignin biosynthesis and auxin signaling to regulate plant growth.This study suggests that McMYB4 participates in the abiotic resistance and growth of apple in response to temperature changes by regulating phenylpropanoid metabolism and hormone signaling.
基金supported by the grants from the National Natural Science Foundation of China (Nos.31271582 and 31200213)China Postdoctoral Science Foundation (No.2012M510410)Beijing Scientific Research Foundation for Scholars Returned from Overseas,and Beijing Municipal Commission of Education (No.010135336400)
文摘Adult stem cells or progenitors are essential for maintaining the normal structure and function of adult tissues （i.e., ho- meostasis）. One of the best examples is the adult intestinal epithelium which is constantly renewed by the progeny of intestinal stem cells （ISCs）. The proliferation and differentiation of adult stem cells must be tightly controlled in order to maintain resident tissue homeostasis. Mis-regulation of stem cell proliferation and differentiation leads to depletion or excessive proliferation of stem cells, eventually resulting in severe diseases such as cancer （Radtke and Clevers, 2005; Morrison and Spradling, 2008）. Understanding the detailed regulatory mechanisms of stem cell proliferation and differ- entiation will shed insights into the causes of related human diseases.
