不同pH和不同氮素形态对小麦根中钙分布的影响

Effects of pH and N forms on the distribution of Ca^(2+) in wheat root

利用电镜技术研究了不同pH(4.0和6.0)和氮形态(NH4+-N和NO3--N)对小麦根系超微结构及根中Ca2+分布的影响。结果表明,1)pH 4.0处理下细胞结构中Ca2+明显少于pH 6.0处理;2)低pH造成质壁分离;3)铵态氮源处理下细胞结构中Ca2+明显少于硝态氮源处理,尤其体现在细胞间质、细胞壁、细胞膜上;4)铵态氮源处理也会导致细胞出现质壁分离,细胞结构松散,胞质外流;低pH加重这些现象。

Transmission electron microscopy was used to observe effects of two pH levels（4.0 and 6.0）and nitrogen forms （NH4^＋ -N,NO3^- -N） on the root ultrastructure and Ca^2＋ distribution in wheat root. Results obtained were the following： 1） Ca^2＋ content in wheat root cells at the pH 4.0 was lower than that at pH 6.0; 2） Low pH could induce plasmolysis of wheat root cells; 3） Ca2 ~ in wheat root cells, especially in intercellular substances, cell wall and cell membrane, with NH4^＋ - N as nitrogen source was significant lower than NO3^- - N; and 4）Ammonium nitrogen was also able to induce plasmolysis, structure loss and cytoplasm outflow of wheat root cells. Low pH could exacerbate these symptoms.