Tomato grafting onto Torubamu (Solanum melongena): miR166a and miR395b reduce scion Cd accumulation by regulating sulfur transport
Tomato grafting onto Torubamu (Solanum melongena): miR166a and miR395b reduce scion Cd accumulation by regulating sulfur transport
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DOI：
10.1007/s11104-020-04564-7
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发表时间：
2020-05-26
期刊：
影响因子：
4.9
通讯作者：
Liu, Wan
中科院分区：
文献类型：
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作者：
He, Lei;Wang, Hetong;Liu, Wan
目的探讨番茄嫁接Torubamu （Solanum melongena）降低番茄镉（Cd）积累的机制。方法将番茄植株嫁接到Torubamu砧木上，在对照土壤和含2.0或5.0 mg•kg−1Cd的土壤中生长30 d。结果嫁接到Torubamu砧木上后，番茄植株叶片中Cd和总硫的积累量分别下降到未嫁接番茄植株的4.1 ~ 11.7%和25.0 ~ 36.7%。此外，miR166a和miR395b在番茄接穗中的表达显著增加。烟草双荧光素酶（LUC）测定和农杆菌介导的番茄遗传转化证实，miR166a和miR395b靶向phavoluta （PHV）、Revolute（REV）、III类同位结构域Leucine Zipper（HD-ZIP）、硫酸盐转运蛋白2；1（SULTR2;1）、ATP硫酰化酶（APS） （APS1/3）和高亲和硫酸盐转运蛋白（HAST）基因，这些基因直接或间接参与硫酸盐转运。结论基于miR166a/395b转化番茄接穗在2.0 mg•kg−1Cd土壤中镉与硫积累的相关关系（r2= 0.91）和miR166a/395b转化番茄接穗的镉与硫积累的相关关系（r2= 0.96-0.98），认为嫁接Torubamu砧木可以减少镉的积累，这主要是由于miR166a和miR395b具有硫酸盐转运调节能力。了解这一机制对耐Cd育种具有重要意义。
AimsThis study aims to understand the mechanism by which grafting tomato (Solanum lycopersicum) onto Torubamu (Solanum melongena) reduces cadmium (Cd) accumulation in tomato.MethodsTomato plants were grafted onto Torubamu rootstocks, and both the un-grafted and grafted tomato plants were grown in the control soil and soil that contained 2.0 or 5.0 mg•kg−1Cd for 30 d.ResultsGrafting onto Torubamu rootstock markedly reduced the accumulation of both Cd and total sulfur in the leaves of tomato plants to 4.1–11.7% and 25.0–36.7% of the values in the un-grafted tomato plants, respectively. Moreover, the expression of miR166a and miR395b markedly increased in tomato scions. Tobacco dual-luciferase (LUC) assays and Agrobacterium-mediated tomato genetic transformation verified that miR166a and miR395b targetedPhavoluta(PHV),Revolute(REV),Class III Homeodomain Leucine Zipper(HD-ZIP),Sulfate transporter 2;1(SULTR2;1),ATP sulfurylase(APS) (APS1/3), andHigh-affinity sulfate transporter(HAST) genes, which are directly or indirectly responsible for sulfate transport.ConclusionsBased on the correlations between the Cd and sulfur accumulation in the tomato scions (r2= 0.91) and in the miR166a/395b-transformed tomato scions (r2= 0.96–0.98) grown in the soil with 2.0 mg•kg−1Cd, we conclude that tomato grafting onto Torubamu rootstock can reduce Cd accumulation because of the sulfate transport regulatory ability of miR166a and miR395b. Understanding this mechanism can be of great benefit for Cd tolerance breeding.