苹果自交不亲和是由于自花授粉后花柱S-RNase进入花粉管影响其生长所致，但其作用机制尚不明确。本课题组以S-RNase为诱饵筛选花粉cDNA文库获得一个含有微丝结合结构域的未知基因，命名为MdMVG；体外添加反义寡核苷酸链培养花粉沉默该基因后再用S-RNase处理发现花粉管生长减缓，顶端呈圆柱形膨大，与对照相比短小微丝碎片增多；蛋白质体外共沉淀实验证明MdMVG能够切割微丝。鉴于此，本研究首先利用体内外互作实验进一步验证MdMVG与S-RNase的互作关系；其次，通过S-RNase与MdMVG蛋白体外孵育后共沉淀明确S-RNase能否促进MdMVG切割微丝；再次，寻找MdMVG转录因子，证明S-RNase与MdMVG结合是否为负反馈调节调控其切割花粉管微丝；最后，MdMVG转基因验证其是否参与了自交不亲和反应。最终明确苹果花粉MdMVG蛋白在S-RNase作用下参与自交不亲和反应的机制。

Apple (Malus×domastica) shows gametophytic self-incompatibility which is due to the toxic effect of the S-RNase to the pollen tubes. But the molecular mechanism is still unclear. In this research, we obtained an unknown function protein from apple by yeast two-hybrid screening which contained actin binding domain, and named MdMVG. We used a phosphorothioated antisense oligodeoxynucleotide to down-regulate MdMVG expression in the pollen tube and then added to S-RNase. The results we found that the growth rate of pollen tube growth is slow,top cylindrical enlargement; the short actin fragment is much more than control.Co-precipitation of proteins in vitro experiment showed that MdMVG could cut actin filaments. In the view of this,firstly, we use protein interaction experiments in vivo to further verify the interaction relationship between MdMVG and S-RNase; secondly, co-precipitation experiment to demonstrate that S-RNase could promote MdMVG to cut filament; then in order to verify that S-RNase could bind with MdMVG and negative feedback regulate the cutting reaction in pollen tube, we use yeast two hybrid experiment to find the transcription factor of MdMVG; at last, we use transgenic experiment to confirm that MdMVG participate in the self-incompatibility. Finally, we could clarify that MdMVG play a role in self-incompatibility reaction by the function of S-RNase.