Najeeb Ullah, Tan Daniel K Y, Bange Michael P, Atwell Brian J
The University of Sydney, Sydney Institute of Agriculture, School of Life and Environmental Sciences, Faculty of Science, Sydney, NSW 2015, Australia.
Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
Funct Plant Biol. 2018 Feb;45(3):340-349. doi: 10.1071/FP17184.
Soil waterlogging and subsequent ethylene release from cotton (Gossypium hirsutum L.) tissues has been linked with abscission of developing cotton fruits. This glasshouse study investigates the effect of a 9-day waterlogging event and CO2 enrichment (eCO2, 700 parts per million (ppm)) on a fully linted cultivar 'Empire' and a lintless cotton mutant (5B). We hypothesised that cotton performance in extreme environments such as waterlogging can be improved through mitigating ethylene action. Plants were grown at 28:20°C day:night temperature, 50-70% relative humidity and a 14:10 light:dark photoperiod under natural light and were exposed to waterlogging and eCO2 at early reproductive growth. Ethylene synthesis was inhibited by spraying aminoethoxyvinylglycine (830ppm) 1 day before waterlogging. Waterlogging significantly increased ethylene release from both cotton genotypes, although fruit production was significantly inhibited only in Empire. Aminoethoxyvinylglycine consistently reduced waterlogging-induced abscission of fruits, mainly in Empire. Limited damage to fruits in 5B, despite increased ethylene production during waterlogging, suggested that fruit abscission in 5B was inhibited by disrupting ethylene metabolism genetically. Elevated CO2 promoted fruit production in both genotypes and was more effective in 5B than in Empire plants. Hence 5B produced more fruits than Empire, providing additional sinks (existing and new fruit) that enhanced the response to CO2 enrichment.
土壤渍水以及随后棉花（陆地棉）组织中乙烯的释放与发育中的棉铃脱落有关。这项温室研究调查了为期9天的渍水事件和二氧化碳富集（eCO2，百万分之700（ppm））对完全有棉绒的品种‘帝国’和无棉绒棉花突变体（5B）的影响。我们假设，通过减轻乙烯的作用，可以改善棉花在渍水等极端环境中的表现。植株在白天28℃、夜间20℃的温度、50 - 70%的相对湿度以及14:10的光照:黑暗光周期下，在自然光下生长，并在生殖生长早期暴露于渍水和eCO2环境中。在渍水前1天喷洒氨基乙氧基乙烯基甘氨酸（830ppm）以抑制乙烯合成。渍水显著增加了两种棉花基因型的乙烯释放量，尽管只有‘帝国’品种的果实产量受到显著抑制。氨基乙氧基乙烯基甘氨酸持续减少了渍水诱导的果实脱落，主要是在‘帝国’品种中。尽管在渍水期间5B的乙烯产量增加，但对果实的损害有限，这表明5B的果实脱落是通过基因破坏乙烯代谢而受到抑制。二氧化碳浓度升高促进了两个基因型的果实产量，并且在5B中比在‘帝国’植株中更有效。因此，5B比‘帝国’品种结出更多果实，提供了额外的库（现有和新的果实），增强了对二氧化碳富集的响应。
