蔬菜硝酸盐积累生理机制研究进展

蔬菜是一种富氮、喜硝的作物,蔬菜硝酸盐污染严重威胁人们的健康,这一问题引起了人们的普遍关注。蔬菜根系以主动吸收为主的方式吸收硝酸根离子,在逆电化学势梯度(170-250mv)下,硝酸根离子以离子态通过共质体途径进入根部内部。在硝酸还原酶的作用下,硝酸盐被还原为亚硝酸盐。硝酸盐的吸收、转运、还原不协调就会导致蔬菜中硝酸盐和亚硝酸盐积累过量,产生污染。蔬菜种类和品种、肥料种类和用量以及蔬菜生长的环境条件(包括光、温、水、气等因子)等因素会影响蔬菜中硝酸盐的积累。

Progress in Physiological Mechanism of Nitrate Accumulation in Vegetable

Vegetable is nitrophile and always accumulate NO3 -. NO3 - pollution in vegetables damages people'' s health seriously, causing a great concern. Vegetable'' s roots absorb NO3 - mainly by the way of active absorption. Under retro-electrochemical gradient (170-250mv), NO3 - is absorbed into the interior of root through symplast in a state of ion. NO3 - is deoxidized into NO2 - by nitrate reductase. The unharmo-nization of absorption, transportation and reduction of nitrate can bring about nitrate and nitrite accumulation excessively in vegetable. Nitrite accumulation can be affected by species and varieties of vegetables, fertilizer types and loading levels, and vegetable growth environments factors (light, temperature, water and CO2).