UV B radiation promoted the expression of PAL and resulted in the accumulation of flavonoids in the leaves of spinach and Chinese cabbage.

• UV－B辐射诱导菠菜和小白菜叶片内苯丙氨酸解氨酶（PAL）活性迅速升高，并导致其体内吸收UV－B的类黄酮化合物大量积累。