【作者】 张晶晶；

【导师】 刘国库；

【作者基本信息】 河北农业大学 ， 作物栽培学与耕作学， 2025， 硕士

【摘要】 猪苓(Polyporus umbellatus(Pers.)Fries)作为一种重要的药用真菌,其产量受多种环境因素的影响,干旱胁迫是其中之一。本研究以吉林省长白山(S1)、河北省白石山(S2)、云南省鸡足山(S3)3个地区的猪苓菌株为材料,采用不同质量浓度聚乙二醇6000(PEG-6000)模拟干旱胁迫,分析了干旱胁迫下3个菌株生物量、渗透调节物质、抗氧化酶活性、丙二醛(MDA)、麦角甾醇、糖代谢关键酶的动态变化,并通过相关性分析、主成分分析(PCA)和隶属函数法综合评价菌株抗旱性,主要结果如下:1.干旱胁迫对猪苓菌株生物量的影响:3个地区猪苓菌株在50 g/L PEG-6000处理下,生物量整体呈上升趋势,随干旱胁迫程度的加深,其生物量积累均下降,且始终小于对照组;但随着胁迫时间的延长,其生物量均出现不同程度的增长。在3个菌株中,S3菌株对干旱胁迫最为敏感,生物量保留率最小12.21%;S1菌株次之,生物量保留率55.32%;S2菌株生物量保留率最大67.54%。2.干旱胁迫对猪苓菌株渗透调节机制的影响:随干旱胁迫程度的加深,S1菌株和S3菌株的脯氨酸(Pro)和可溶性蛋白含量均呈先上升后下降的趋势,但S3菌株在第12 d 200 g/L PEG-6000处理下Pro含量仅为0.98μg/g,可溶性蛋白含量为1.89mg/g;随胁迫时间的延长,S1菌株和S2菌株Pro和可溶性蛋白的含量均出现不同程度的增长。S2菌株随干旱胁迫程度的加深和胁迫时间的延长,其Pro和可溶性蛋白含量均呈上升趋势,且在第12 d 200 g/L PEG-6000处理下,S2菌株的Pro和可溶性蛋白含量显著高于S1菌株和S2菌株。3.干旱胁迫对猪苓菌株抗氧化系统和膜稳定性的影响:随胁迫时间的延长3个菌株的超氧化物歧化酶(SOD)活性均呈下降的趋势,而过氧化氢酶(CAT)、过氧化物酶(POD)以及MDA呈上升趋势,麦角甾醇的含量则先上升后平稳。随胁迫程度的增加,S1菌株的SOD活性在第6 d呈先上升后下降的趋势,之后呈下降趋势,S2菌株则呈先上升后平稳的趋势。S3菌株SOD、POD、CAT以及麦角甾醇随胁迫程度的增加均呈先上升后下降趋势,而MDA呈上升趋势,在200 g/L PEG-6000处理下含量飙升至19.61 nmol/g。S2菌株随胁迫程度加深,其POD和MDA呈上升趋势,而CAT先下降后上升,麦角甾醇则先升后降。4.干旱胁迫下对猪苓菌株多糖积累与糖代谢关键酶活性的影响:随胁迫时间的延长,3个菌株的胞外多糖和胞内多糖均呈上升趋势,随胁迫程度的增加均呈先升后降的趋势,S2菌株在第12 d 200 g/L PEG-6000处理下胞外多糖产量为1.41 g/L,为S1菌株同处理下的1.45倍。3个菌株的UDP-葡萄糖焦磷酸化酶(UGPase)和磷酸葡萄糖异构酶(PGI)活性随胁迫程度增加均呈先升后降的趋势。S2菌株的糖代谢关键酶磷酸葡萄糖变位酶(PGM)呈上升趋势,其PGM和UGPase活性在第12 d 200 g/L PEG-6000胁迫下均显著比S1菌株高。S1菌株在100 g/L PEG-6000胁迫下胞内多糖积累速率最高,但200 g/L PEG-6000胁迫下磷酸葡萄糖异构酶(PGI)活性下降。S3菌株在200 g/L PEG-6000处理时PGM活性骤降至0.28 U/mg,且胞内多糖含量锐减。5.菌株抗逆生理指标与干旱胁迫强度的相关性分析、主成分分析及隶属函数分析:根据相关性分析,在PEG-6000胁迫下,3个菌株的生物量均表现出与PEG-6000的显著负相关性,其中菌株S3的负相关性最为显著。菌株S1和S2中Pro含量与PEG-6000浓度呈显著正相关,而S3则呈负相关。SOD活性在S2中与PEG-6000正相关性,而S1和S3则表现为负相关。可溶性蛋白质在S1和S2中与PEG-6000呈正相关,而S3则呈明显的负相关性。主成分分析表明,前2个主成分累积贡献率达75.95%。综合得分显示,S2菌株在PC2(抗氧化系统)得分最高;S1菌株在PC1(如渗透调节物质)得分突出;S3菌株在所有主成分得分均最低。方差分析验证显示各主成分得分在菌株间存在显著差异(p<0.05),其中S2在PC2得分显著高于其他菌株,S1在PC1得分显著优于S2和S3,通过隶属函数分析,其中得分最高的为S1。结论:揭示了猪苓菌株在干旱胁迫下抗氧化酶活性、渗透调节物质及糖代谢关键酶的动态响应特征及差异。明确了3个地区的猪苓菌株的抗旱性强弱,由强到弱依次为S1>S2>S3。更多还原

【Abstract】 Polyporus umbellatus(Pers.)Fries,an important medicinal fungus,has its yield influenced by various environmental factors,with drought stress being one of them.In this study,strains of Polyporus umbellatus from three regions-Changbai Mountain in Jilin Province(S1),Baishi Mountain in Hebei Province(S2),and Jizu Mountain in Yunnan Province(S3)-were used as materials.Different mass concentrations of polyethylene glycol6000(PEG-6000)were employed to simulate drought stress.The dynamic changes in biomass,osmoregulatory substances,antioxidant enzyme activities,malondialdehyde(MDA),ergosterol,and key enzymes in sugar metabolism of the three strains under drought stress were analyzed.The drought resistance of the strains was comprehensively evaluated through correlation analysis,principal component analysis(PCA),and membership function method.The main results are as follows:1.Effects of drought stress on biomass of Polyporus umbellatus strains:Under 50 g/L PEG-6000 treatment,the biomass of Polyporus umbellatus strains from the three regions generally showed an upward trend.With the intensification of drought stress,biomass accumulation decreased and remained lower than that of the control group.However,with the prolongation of stress time,biomass increased to varying degrees.Among the three strains,S3 was the most sensitive to drought stress,with the lowest biomass retention rate of 12.21%.S1 followed with a biomass retention rate of 55.32%,while S2 had the highest biomass retention rate of 67.54%.2.Effects of drought stress on osmoregulatory mechanisms of Polyporus umbellatus strains:With the increase in drought stress intensity,the proline(Pro)and soluble protein contents in strains S1 and S3 first increased and then decreased.However,under 200 g/L PEG-6000 treatment on day 12,the Pro content in S3 was only 0.98μg/g,and the soluble protein content was 1.89 mg/g.With the prolongation of stress time,the Pro and soluble protein contents in S1 and S2 increased to varying degrees.For strain S2,both Pro and soluble protein contents showed an upward trend with the increase in drought stress intensity and prolongation of stress time.Under 200 g/L PEG-6000 treatment on day 12,the Pro and soluble protein contents of S2 were significantly higher than those of S1 and S3.3.Effects of drought stress on antioxidant system and membrane stability of Polyporus umbellatus strains:With the prolongation of stress time,the superoxide dismutase(SOD)activity of the three strains showed a downward trend,while catalase(CAT),peroxidase(POD),and MDA showed upward trends.The ergosterol content first increased and then stabilized.With the increase in stress intensity,the SOD activity of S1first increased and then decreased on day 6,followed by a continuous decline.In contrast,S2 showed a trend of first increasing and then stabilizing.For S3,SOD,POD,CAT,and ergosterol all first increased and then decreased with increasing stress intensity,while MDA showed a continuous upward trend,surging to 19.61 nmol/g under 200 g/L PEG-6000 treatment.For S2,POD and MDA increased with deeper stress,while CAT first decreased and then increased,and ergosterol first increased and then decreased.4.Effects of drought stress on polysaccharide accumulation and key enzyme activities in sugar metabolism of Polyporus umbellatus strains:With the prolongation of stress time,both extracellular and intracellular polysaccharides of the three strains showed upward trends,while they first increased and then decreased with the increase in stress intensity.Under 200 g/L PEG-6000 treatment on day 12,the extracellular polysaccharide yield of S2was 1.41 g/L,1.45 times that of S1 under the same treatment.The activities of UDP-glucose pyrophosphorylase(UGPase)and phosphoglucose isomerase(PGI)in the three strains first increased and then decreased with increasing stress intensity.The key enzyme in sugar metabolism,phosphoglucomutase(PGM),in S2 showed an upward trend.Both PGM and UGPase activities of S2 were significantly higher than those of S1 under200 g/L PEG-6000 stress on day 12.The intracellular polysaccharide accumulation rate of S1 was highest under 100 g/L PEG-6000 stress,but PGI activity decreased under 200 g/L PEG-6000 stress.Under 200 g/L PEG-6000 treatment,the PGM activity of S3 dropped sharply to 0.28 U/mg,and the intracellular polysaccharide content decreased drastically.5.Correlation analysis,principal component analysis,and membership function analysis of stress-resistant physiological indicators and drought stress intensity:According to correlation analysis,under PEG-6000 stress,the biomass of the three strains showed a significant negative correlation with PEG-6000,with S3 showing the most significant negative correlation.The Pro content in S1 and S2 was significantly positively correlated with PEG-6000 concentration,while S3 showed a negative correlation.SOD activity in S2was positively correlated with PEG-6000,whereas S1 and S3 showed negative correlations.Soluble protein in S1 and S2 was positively correlated with PEG-6000,while S3 showed a significant negative correlation.Principal component analysis indicated that the cumulative contribution rate of the first two principal components reached 75.95%.Comprehensive scores showed that S2 had the highest score in PC2(antioxidant system),S1 excelled in PC1(e.g.,osmoregulatory substances),and S3 had the lowest scores in all principal components.Variance analysis verified significant differences in principal component scores among strains(p<0.05),with S2 scoring significantly higher than others in PC2and S1 performing significantly better than S2 and S3 in PC1.Through membership function analysis,S1 had the highest score.Conclusion:This study revealed the dynamic response characteristics and differences in antioxidant enzyme activities,osmoregulatory substances,and key enzymes in carbohydrate metabolism of Polyporus umbellatus strains under drought stress.The drought resistance of the three strains was ranked as S1>S2>S3.更多还原