在水培条件下,研究了不同氮素水平对小麦幼苗叶绿体色素、色素蛋白复合体含量及其光谱特征的影响.结果显示:(1)氮素水平较低时PSⅡ捕光色素蛋白复合体LHCⅢ在24~30 kD范围内的蛋白含量降低,不供氮时,色素蛋白复合体含量最低,而高分子量区域的蛋白组分相对较为稳定,说明氮素水平影响PSⅡ的多肽组分,而对PSⅠ多肽组分的影响相对较小.(2)室温吸收光谱分析表明,氮素水平较低时结合态色素的含量及比例发生改变,影响植物对光的吸收能力;荧光激发及发射光谱的峰值均随氮素浓度的升高而升高,说明增加施氮量时,叶绿体类囊体中受激发的色素分子数目增加,荧光强度也随之增大;叶绿体蛋白含量在16.86 mg·L-1氮素浓度时最大.
Different nitrogen levels were applied on water-cultivated wheat seedling. The results showed that the contents of pigment protein complexes of PS Ⅱ , particularly for the polypeptides of LHC Ⅱ in the amounts of 24-30 kD,were decreased when the level of nitrogen was lower. The lowest content of pigment protein complexes was shown on no nitrogen applied. The pigment protein complexes of PSI was not significantly affected with changing the nitrogen level. The absorption spectra, fluorescence emission spectra and excitation spage of chloroplast thylakoid-membrane at room temperature increased gradually as the level of nitrogen increased. The content of chlorophyll protein in wheat seedling reached to the tiptop at 16.86 mg· L^-1 of nitrogen.