EDTA和BR对黑麦草铅积累与耐性的调控作用

通过盆栽试验研究了乙二胺四乙酸(EDTA)与植物生长调节剂芸苔素内酯(BR)单施或配施对Pb胁迫条件下黑麦草生长、生理特性及铅富集与转运特征的影响.结果表明,叶面喷施0.05~0.1 mg·L~(-1)的BR提高了黑麦草地上部Pb含量与积累量、植株干重、叶绿素a、叶绿素b、酸溶性巯基(SH)和络合素(PCs)含量.单施2.5 mmol·kg-1EDTA对黑麦草生长没有显著影响,但显著提高了植株Pb含量和积累量;EDTA与BR配施处理中,随着BR浓度的升高,地上部Pb含量与积累量、转移系数和富集系数随之提高,生物量则没有显著变化;叶面喷施0.1 mg·L~(-1)的BR配合根施2.5 mmol·kg~(-1)的EDTA,可使地上部Pb积累量提高8.79倍.BR单施在提高Pb积累的同时,通过提高SH和PCs含量来提高其对Pb的耐性;BR与EDTA配施处理则在进一步提高黑麦草对Pb的富集与转移能力的同时,通过提高As A含量来提高其对Pb胁迫的耐性.

Regulatory effects of EDTA and brassinolide on Pb accumulation and tolerance in Lolium perenne

A pot experiment was conducted to investigate plant growth, physiological characteristics, Pb enrichment and translocation in Lolium perenne enhanced by ethylenediaminetetraacetic acid (EDTA) and brassinolide (BR) applied separately or in combination. For BR treatments, the contents of Chlorophyll a, Chlorophyll b, acid soluble thiol and phytochelatins increased in shoot with 0.05~0.1 mg·L^-1 BR. 2.5 mmol·kg^-1 EDTA treatment significantly increases Pb concentrations and accumulation in the plant, while shows no significant impact on biomass and photosynthetic pigments in shoot. For combined treatments of EDTA and BR, Pb concentrations, accumulation, enrichment factors and transportation factors increase with elevation of BR concentration, while biomass shows no significant change. 0.1 mg·L^-1 BR with 2.5 mmol·kg^-1 EDTA applied in combination can improve Pb accumulation in shoot by 8.79 times. BR treatments can increase Pb accumulation and alleviate Pb stress by increasing SH and PCs contents. BR and EDTA in combination can further increase Pb accumulation capacity, and increase AsA contents in the plant to mitigate growing Pb stress.