外源寡糖对低温胁迫下烟苗生理特性影响及机制研究

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中图分类号：S572.01 文献标识码：A文章编号：1007-5119（2025）04-0027-09

Abstract：Inordertoimprovetheresistanceof tobacoseedlings tolowtemperature stress，thephysiologicalandmolecular mechanisms of oligosaccharides were studied. In this study，the low temperature sensitive tobacco variety "K326" was used as the test materialtostudythefectsoffoliarsprayingwithdiferentconcentrationsofchitosanoligosaccharides，brownalage oligosaccharidesandmannoseoligosaccharidesonthegrowthandphysiologicalcharacteristicsoftobacoseedlingsunderlow temperature stressandtoexplorethe molecularmechanismofehancing tobaccoresistancetolowtemperature.Theresultsshowed thatcompared withthelowtemperaturestressgroup，foliarsprayingofdiferent typesandconcentrationsofoligosaccharidescould significantly increase the maximum leaf area and biomass of tobacco seedlingsby 22.45%-62.84% ，increase root activity and the content of chlorophyll by 32.02%-131.72% and 10.02%-34.76% ，respectively. The content of osmoregulatory substances was increased by more than 14.10% ，significantly increased the activities of antioxidant enzymes，such as superoxide dismutase， peroxidase，catalase，andenhancedtheactivityof glutathionereductase，and inreasedthereduced glutathionecontent.Combned with the afiliation function analysis，it was concluded that tobacco seedlings with foliar spraying of 200mg/L mannose oligosaccharideshadhigherresistance tolow temperature stressthan 500mg/L mannoseoligosaccharides and 200mg/L chitosan oligosaccharides.Furthertranscriptomesequencingaalysisshowedthatmanoseoligosaccharidestreatmentsignificantlyincreased theexpressonofaminoacid degradation，glycerolipid metabolism，redoxenzymeactivityandcatalyticactivity.Thisstudy demonstrated that foliar application of 200mg/L mannose oligosaccharides significantly enhanced the cold stress tolerance of tobacco seedlings，outperformingboth 500mg/L mannose oligosaccharidesand 200mg/L chito oligosaccharide.

Keywords： oligosaccharides; low temperature stress tobacco; physiological characteristics; transcriptome

烟草适宜生长温度为 ，适宜的温度能提高细胞活性，促进根系生长和水分吸收。（剩余14900字）