广播电视英语短句 第 214 课：植物如何使用水-3

Mr. Schroeder says that carbon dioxide level in the atmosphere is much higher now than they were in the past. Schroeder 先生说现在空气中的二氧化碳含量比过去高得多。

However, he says, many plants are closing their poles in order to hold in more water. 然而，他说，许多植物正在关闭它们的孔以保存水分。

He and his team have identified proteins that control the tightening of a plant's pores. 他和他的团队已经确定了收缩植物毛孔的蛋白质。

The proteins are enzymes called carbonic and hydras. 这一蛋白质叫做碳水化酶。

The findings were published last month in the journal nature cell biology. 这些发现上月发表在细胞生物学期刊上。