Cotton(Gossypium spp.) yield is reduced by stress. In this study, high temperature(HT) suppressed the expression of the jasmonic acid(JA) biosynthesis gene allene oxide cyclase 2(GhAOC2), reducing JA content and causi...Cotton(Gossypium spp.) yield is reduced by stress. In this study, high temperature(HT) suppressed the expression of the jasmonic acid(JA) biosynthesis gene allene oxide cyclase 2(GhAOC2), reducing JA content and causing male sterility in the cotton HT-sensitive line H05. Anther sterility was reversed by exogenous application of methyl jasmonate(MeJA) to early buds. To elucidate the role of GhAOC2 in JA biosynthesis and identify its putative contribution to the anther response to HT, we created gene knockout cotton plants using the CRISPR/Cas9 system. Ghaoc2 mutant lines showed male-sterile flowers with reduced JA content in the anthers at the tetrad stage(TS), tapetum degradation stage(TDS), and anther dehiscence stage(ADS). Exogenous application of MeJA to early mutant buds(containing TS or TDS anthers) rescued the sterile pollen and indehiscent anther phenotypes, while ROS signals were reduced in ADS anthers. We propose that HT downregulates the expression of GhAOC2 in anthers, reducing JA biosynthesis and causing excessive ROS accumulation in anthers, leading to male sterility. These findings suggest exogenous JA application as a strategy for increasing male fertility in cotton under HT.展开更多
The plasma membrane Ca2+-ATPase(PMCA)pumps play an important role in the maintenance of precise levels of intracellular Ca2+[Ca2+]i,essential to the functioning of neurons.In this article,we review evidence showing ag...The plasma membrane Ca2+-ATPase(PMCA)pumps play an important role in the maintenance of precise levels of intracellular Ca2+[Ca2+]i,essential to the functioning of neurons.In this article,we review evidence showing age-related changes of the PMCAs in synaptic plasma membranes(SPMs).PMCA activity and protein levels in SPMs diminish progressively with increasing age. The PMCAs are very sensitive to oxidative stress and undergo functional and structural changes when exposed to oxidants of physiological relevance.The major signatures of oxidative modification in the PMCAs are rapid inactivation,conformational changes,aggregation, internalization from the plasma membrane and proteolytic degradation.PMCA proteolysis appears to be mediated by both calpains and caspases.The predominance of one proteolytic pathway vs the other,the ensuing pattern of PMCA degradation and its consequence on pump activity depends largely on the type of insult,its intensity and duration.Experimental reduction of PMCA expression not only alters the dynamics of cellular Ca2+ handling but also has a myriad of downstream conse-quences on various aspects of cell function,indicating a broad role of these pumps.Age-and oxidation-related down-regulation of the PMCAs may play an important role in compromised neuronal function in the aging brain and its several-fold increased susceptibility to neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease,and stroke.Therapeutic approaches that protect the PMCAs and stabilize[Ca2+]i homeostasis may be capable of slowing and/or preventing neuronal degeneration.The PMCAs are therefore emerging as a new class of drug targets for therapeutic interventions in various chronic degenerative disorders.展开更多
采用营养液水培,以抗低氧能力不同的2个黄瓜品种为试材,研究了C a2+对黄瓜幼苗植株生长和根系无氧呼吸酶活性的影响。结果表明,在低氧胁迫下,LDH、PDC和ADH活性提高程度与幼苗的抗低氧性和C a2+浓度密切相关。与抗低氧性较弱的“中农8...采用营养液水培,以抗低氧能力不同的2个黄瓜品种为试材,研究了C a2+对黄瓜幼苗植株生长和根系无氧呼吸酶活性的影响。结果表明,在低氧胁迫下,LDH、PDC和ADH活性提高程度与幼苗的抗低氧性和C a2+浓度密切相关。与抗低氧性较弱的“中农8号”相比,抗低氧性强的“绿霸春4号”幼苗根系LDH活性增加缓慢,而PDC和ADH活性增加幅度较大,因此增强了植株对低氧胁迫的抗性。低氧胁迫下,营养液中8 mm o l.L-1C a2+处理能显著提高根系ADH活性,降低LDH和PDC活性,0 mm o l.L-1C a2+处理表现出相反的规律。由此可以说明,低氧胁迫下,C a2+能够提高ADH活性,降低LDH和PDC活性,可增强黄瓜植株对低氧胁迫的抗性。展开更多
为了研究盐渍生境对盐生植物碱茅Puccinellia china mpoensis体内部分信号分子的影响,采用不同浓度NaCl溶液处理碱茅植株,对幼苗叶片中部分信号分子及相关蛋白测定和分析。结果发现,低盐下碱茅无胁迫反应,高盐胁迫下,碱茅脱落酸(ABA)含...为了研究盐渍生境对盐生植物碱茅Puccinellia china mpoensis体内部分信号分子的影响,采用不同浓度NaCl溶液处理碱茅植株,对幼苗叶片中部分信号分子及相关蛋白测定和分析。结果发现,低盐下碱茅无胁迫反应,高盐胁迫下,碱茅脱落酸(ABA)含量升高,生长素(IAA)、赤霉素(GA)含量均下降,细胞分裂素(ZR)含量趋于稳定;碱茅NAD激酶(NADKase)活性升高,提高代谢调节能力;同时Ca2+-ATPase活性增加,是对盐胁迫引起Ca2+浓度升高而做出的胁迫反应。表明了碱茅通过胞间信号相对含量的变化,调节NADKase活性、Ca2+-ATPase活性,提高耐盐能力。展开更多
基金funding support from the National Natural Science Foundation of China (32072024)the Fundamental Research Funds for the Central Universities (2021ZKPY019)the National Key Research and Development Program of China (2018YFD0100403, 2016YFD0101402)。
文摘Cotton(Gossypium spp.) yield is reduced by stress. In this study, high temperature(HT) suppressed the expression of the jasmonic acid(JA) biosynthesis gene allene oxide cyclase 2(GhAOC2), reducing JA content and causing male sterility in the cotton HT-sensitive line H05. Anther sterility was reversed by exogenous application of methyl jasmonate(MeJA) to early buds. To elucidate the role of GhAOC2 in JA biosynthesis and identify its putative contribution to the anther response to HT, we created gene knockout cotton plants using the CRISPR/Cas9 system. Ghaoc2 mutant lines showed male-sterile flowers with reduced JA content in the anthers at the tetrad stage(TS), tapetum degradation stage(TDS), and anther dehiscence stage(ADS). Exogenous application of MeJA to early mutant buds(containing TS or TDS anthers) rescued the sterile pollen and indehiscent anther phenotypes, while ROS signals were reduced in ADS anthers. We propose that HT downregulates the expression of GhAOC2 in anthers, reducing JA biosynthesis and causing excessive ROS accumulation in anthers, leading to male sterility. These findings suggest exogenous JA application as a strategy for increasing male fertility in cotton under HT.
文摘The plasma membrane Ca2+-ATPase(PMCA)pumps play an important role in the maintenance of precise levels of intracellular Ca2+[Ca2+]i,essential to the functioning of neurons.In this article,we review evidence showing age-related changes of the PMCAs in synaptic plasma membranes(SPMs).PMCA activity and protein levels in SPMs diminish progressively with increasing age. The PMCAs are very sensitive to oxidative stress and undergo functional and structural changes when exposed to oxidants of physiological relevance.The major signatures of oxidative modification in the PMCAs are rapid inactivation,conformational changes,aggregation, internalization from the plasma membrane and proteolytic degradation.PMCA proteolysis appears to be mediated by both calpains and caspases.The predominance of one proteolytic pathway vs the other,the ensuing pattern of PMCA degradation and its consequence on pump activity depends largely on the type of insult,its intensity and duration.Experimental reduction of PMCA expression not only alters the dynamics of cellular Ca2+ handling but also has a myriad of downstream conse-quences on various aspects of cell function,indicating a broad role of these pumps.Age-and oxidation-related down-regulation of the PMCAs may play an important role in compromised neuronal function in the aging brain and its several-fold increased susceptibility to neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease,and stroke.Therapeutic approaches that protect the PMCAs and stabilize[Ca2+]i homeostasis may be capable of slowing and/or preventing neuronal degeneration.The PMCAs are therefore emerging as a new class of drug targets for therapeutic interventions in various chronic degenerative disorders.
文摘采用营养液水培,以抗低氧能力不同的2个黄瓜品种为试材,研究了C a2+对黄瓜幼苗植株生长和根系无氧呼吸酶活性的影响。结果表明,在低氧胁迫下,LDH、PDC和ADH活性提高程度与幼苗的抗低氧性和C a2+浓度密切相关。与抗低氧性较弱的“中农8号”相比,抗低氧性强的“绿霸春4号”幼苗根系LDH活性增加缓慢,而PDC和ADH活性增加幅度较大,因此增强了植株对低氧胁迫的抗性。低氧胁迫下,营养液中8 mm o l.L-1C a2+处理能显著提高根系ADH活性,降低LDH和PDC活性,0 mm o l.L-1C a2+处理表现出相反的规律。由此可以说明,低氧胁迫下,C a2+能够提高ADH活性,降低LDH和PDC活性,可增强黄瓜植株对低氧胁迫的抗性。
文摘为了研究盐渍生境对盐生植物碱茅Puccinellia china mpoensis体内部分信号分子的影响,采用不同浓度NaCl溶液处理碱茅植株,对幼苗叶片中部分信号分子及相关蛋白测定和分析。结果发现,低盐下碱茅无胁迫反应,高盐胁迫下,碱茅脱落酸(ABA)含量升高,生长素(IAA)、赤霉素(GA)含量均下降,细胞分裂素(ZR)含量趋于稳定;碱茅NAD激酶(NADKase)活性升高,提高代谢调节能力;同时Ca2+-ATPase活性增加,是对盐胁迫引起Ca2+浓度升高而做出的胁迫反应。表明了碱茅通过胞间信号相对含量的变化,调节NADKase活性、Ca2+-ATPase活性,提高耐盐能力。
