摘要
[目的]茶叶富含有利于人体健康的多糖、咖啡因、多酚和氨基酸等有益物质,但茶树能够在正常含氟(F)土壤中超积累F,导致过量饮茶易诱发氟斑牙和氟骨病的发生。因此,降低茶叶中的F含量对人体健康具有重要意义。[方法]以‘福鼎’大白茶茶籽为研究对象,通过激光共聚焦和非损伤微测技术研究Ca^(2+)信号在阴离子通道抑制剂4,4-二异硫氰-2,2-二磺酸(DIDS)抑制茶树吸收F过程中的作用。[结果]随着DIDS前处理时间的延长,显著削弱了茶树对F的吸收富集。同时DIDS调控了茶树根尖成熟区区域A和B的Ca^(2+)荧光强度的反向变化,区域A从858.42降低至565.42 AU,区域B从499.28升至570.42 AU;同时DIDS显著刺激了茶树根部成熟区Ca^(2+)的跨膜运输,平均外排量从静息量的9.43提高至350.35pmol·cm-2·s-1。此外,Ca^(2+)螯合剂EGTA前处理分别削弱了DIDS对Ca^(2+)信号强度的增强和对F的吸收抑制作用。[结论]茶树根尖成熟区Ca^(2+)信号可能通过跨膜运输参与了DIDS抑制茶树对F的吸收富集。
[Objectives]Tea plant is beneficial for people＇s health due to the elements of polysaccharide,caffeine,polyphenol and amino acid. However,tea plants（ Camellia sinensis L.） can accumulate large amounts of fuoride（ F）,while the over-intake of fluoride through drinking tea can cause dental fluorosis and fluorosis of bone. Therefore,the research of reducing F content in tea plants has an important effect on human＇s body health. [Methods]In this study,‘Fuding＇variety of tea plant was used as materials to carry out the experiments. Using laser confocal scanning microscopy（ LCSM） and Non-invasive Micro-test Technique（ NMT） approaches,the role of Ca^（2＋）signal on DIDS（ 4,4-diisothiocyanostilbene-2,2-disulfonic acid）-inhibited F accumulation in tea plants was investigated. [Results]The pretreatment of DIDS significantly inhibited F accumulation in tea plants. DIDS altered Ca^（2＋）fluorescence intensity in the mature zone of tea root,which decreased from 858.42 to 565.42 AU in region A and increased from 499.28 to 570.42 AU in region B. In addition,DIDS significantly stimulated Ca^（2＋）efflux from the root mature zone cells,ranging from 9.43 to 350.35 pmol·cm-2·s-1. Whilst,EGTA pretreatment inhibited DIDS-induced the increase of Ca^（2＋）fluorescence intensity in tea lateral roots,and also significantly impaired DIDSdecreased F accumulation in tea plants. [Conclusions]Taken together,the endogenous Ca^（2＋）in the mature zone of tea root might participate in the F accumulation in tea plants inhibited by the pretreatment of DIDS.
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2016年第3期441-447,共7页
Journal of Nanjing Agricultural University
基金
国家自然科学基金项目(31272254
41071158)
