硝普钠对NaCl胁迫下长春花幼苗光合及生物碱的影响

EFFECTS OF SNP ON PHOTOSYNTHESIS AND ALKALOID CONTENT OF CATHARANTHUS ROSEUS SEEDLINGS UNDER NaCl STRESS

在温室沙培条件下,研究了不同浓度外源NO供体硝普钠(SNP)对50 mmol L-1NaCl胁迫下长春花幼苗生长、光合特性和生物碱的影响。结果表明:(1)在用0.05～2.0 mmol L-1 SNP缓解50 mmol L-1NaCl胁迫中,0.1mmol L-1 SNP缓解效果最好,长春花幼苗的鲜重、干重、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和过氧化物酶(POD)活性分别较S1(50 mmol L-1NaCl)处理显著增加18.8%、13.9%、20.7%、19.1%、8.5%和32.6%,而细胞间隙CO2浓度(Ci)较S1处理显著降低10.3%。(2)当SNP浓度增加到0.5mmol L-1时,色氨酸脱羧酶(TDC)活性、吲哚总碱、长春碱、长春质碱、长春新碱和文多灵含量均达到最高,分别较S1显著增加33.4%、26.9%、32.3%、27.4%、68.8%和50.2%。综上所述:在50 mmol L-1NaCl胁迫下,0.1 mmol L-1SNP对提高光合作用,促进生长,增加生物量的作用最显著;而0.5 mmol L-1 SNP则对提高TDC活性,促进吲哚总碱和4种主要生物碱合成积累作用最显著。

A sand culture experiment was conducted in greenhouse to study the effects of exogenous nitric oxide donor（SNP） on growth,photosynthetic characteristics and alkaloids contents of Catharanthus roseus seedlings under 50 mmol L-1 NaCl stress.The results show：（1） 0.1 mmol L-1 SNP was the highest in effect of alleviating the stress caused by 50 mmol L-1 NaCl,and significantly increased fresh weight,dry weight,Pn,Gs,Tr and POD activity by 18.8%,13.9%,20.7%,19.1%,8.5% and 32.6% respectively,but decreased Ci by 10.3% as against Treatment S1（50 mmol L-1 NaCl）.（2） In Treatment S4,where the concentration of SNP increased to 0.5 mmol L-1,the TDC activity,total indole alkaloids,Vinblastine,Catharanthine,Vincristine and Vindolin contents of the Catharanthus roseus were the highest,compared with Treatment S1,they increased 33.4%,26.9%,32.3%,27.4%,68.8% and 50.2% respectively.To sum up,0.1 mmol L-1SNP is the best at increasing photosynthesis,promoting growth and raising biomass,however 0.5 mmol L-1 SNP is the best at improving synthesis of total indole alkaloids and four main kinds of alkaloids.