谷子（Setaria italica）是我国北方重要的粮食作物。土壤中重金属铬（Cr6+）污染会对谷子生产造成严重影响，并威胁人类健康。如何减轻这种危害并减少其在作物中的积累成为重要的研究课题，但目前深入的机制研究非常有限。.硫化氢（H2S）是继NO和CO之后第三种气体信号分子。前期试验证实，生理浓度H2S处理可以显著提高谷子幼苗对Cr6+的耐受性，并显著减少其在植物体内的积累。而且这种生理作用的发挥受到的Ca2+的调节。结合已有文献，我们推测其作用机制可能是Ca2+通过CaM蛋白激活TGA3转录因子,以调节H2S生成。这一推测的关键环节得到实验证实：TGA3转录因子确实可以与内源H2S合成酶编码基因启动子特异性结合。.基于此，本项目就Ca2+→CaM→TGA3→H2S这一通路各个环节，从分子、细胞以及表型水平进行系统研究，为减轻重金属对作物的危害、减少其在作物中积累提供有益的理论支撑。

Foxtail millet (Setaria italica) is an important crop in north China.Chromium (Cr6 +) is one of heavy metal pollution of soil in our country which impact on crop growth, development directly, and do harm to human health through food chain. How to reduce the harm of heavy metals and reduce their accumulation in crops is an important topic. But the reports on the deep mechanism is very limited..Hydrogen sulfide (H2S) is the third recognized gasotransmitter after NO and CO, and plays important physiological roles in plants. Our previous studies discovered that H2S treatment in physiological concentration could significantly increase the tolerance of millet seedlings to Cr6+, and reduced its accumulation in the plants..In addition, we found that the H2S function was regulated by Ca2+ signal. Based on our data and the existing literature, we hypothesized that Ca2+ ion can activate transcription factors TGA3,through CaM, thereby affecting the prodution of endogenous H2S. .The key link of this theoretical conject has been confirmed by gel shift assay: TGA3 can really bind in the the promoter region of LCD gene which encodes the enzyme producing endogenous H2S in plants..Based on this, we plan to carry out the systematicaly researches on the pathway, Ca2+→CaM→TGA3→H2S, on the level of molecular biology, cell biology and phenotype levels.This research may provide useful theoretical support to reduce the heavy metal hazards and its accumulation in the crops.