叶子黄了用英语怎么说

"Leaf yellowing" 用英语表达为 "yellowing of leaves"。来源是因为叶子黄了，颜色就是黄色。

英文例句：

The leaves on the tree have started yellowing, indicating that it may be in distress.
The yellowing of leaves on the plant is a sign of nutrient deficiency.
The leaves on my tomato plants have been yellowing and falling off, what could be causing this?

中文翻译：

树上的叶子开始变黄了，这表明它可能处于困境之中。
植物上叶子变黄是营养缺乏的信号。
我的西红柿植株的叶子变黄并脱落，这是为什么？