Influence of lanthanum on chloroplast ultrastructure of soybean leaves under ultraviolet-B stress

In order to investigate the effects of lanthanum(III) on cell ultrastructure of soybean leaves under elevated ultraviolet-B irradiation (UV-B, 280–320 nm), the chloroplast ultrastructure of soybean seedlings was studied by hydroponics under laboratory conditions. The results showed that the thylakoid in chloroplast was orderly and clearly as soybean leaves were pretreated by La(III). The thylakoid was indistinctly disordered, expanded and even indiscoverable in the chloroplast under UV-B stress. The impact on the thylakoid by the high intensity UV-B irradiation (T2) was bigger than that by the low intensity UV-B irradiation (T1). However, the destruction of the chloroplast structure caused by UV-B stress was alleviated by La(III), and the arrangement of the thylakoid in the chloroplast became orderly and clearly. The effect of the alleviation by La(III) under the low intensity UV-B irradiation (T1) was better than that under the high intensity UV-B irradiation (T2).