The Interactive Effect Of Light And Different Nitrogen Forms On Assimilation Of Carbon And Nitrogen In Wheat Seeding

The wheat seeding of Lumai 22 were cultivated under two light Conditions and different nitrogen forms,Then Joined DLGA,the inhibitor of carbon circulation(D,L-glyceraldehyde),or MSX,an inhibitor of glutamine synthetase．Study the effect of light and different nitrogen forms on the metabolism of carbon and nitrogen in wheat seedling．Expound the relationship between carbon and nitrogen metabIolism further．The result shoWS:1．The plant grown under hi。gh light density had high chlorophyll contentcompared with those under low light density,also a higher activity of nitratereductase and glutamine synthetase,a higher content of soluble protein and soluble sugar．No matter which kind of nitrogen source deal with,content of soluble protein was higher than contrast under two kinds of light condition, but contrast had higher contents of total soluble sugar．Nitrate reductase activity in wheat seedings leaves treated by NH₄N0₃ and Ca(N0₃)₂ was higher than contrast,nitrate reductase activity in wheat seeding leaves treated by (NH₄)₂S0₄ was lower than contrst．2．The effect of different nitrogen forms on glutamine synthetase in wheat seedings leaves is different,Ca(N03₎₂>NH₄NO₃>(NH₄)₂S0₄>CK．3．After adding nitrogen metabolism inhibitor MSX,an inhibitor of glutamine synthetase．nitrate reductase activity increased under two kinds light condition, the rising ranges of nitrate reductase activity in wheat seeding leaves^eated by (NH₄)₂S0₄ was highest．glutamine synthetase activity and protein content decreased．but contents of total soluble sugar increased．The rising ranges of content of soluble sugar under low high light density． 1ight density was higher than those under 4．After adding D,L-glyceraldehydes,an inhibitor of phosphoribulokinase, nitrate reductase activity,glutamine synthetase activity,contents of total soluble protein reduced after beng raised first,co^ents of total soluable sugar decreased all the time．The rising ranges of nitrate reductase in wheat seeding leaves under hi gh light density was smaller than those under low light density．This results of the test is explained:There was important interactive effect of light and different nitrogen forms on carbon and nitrogen metabolism in wheat seeding,which Can promote nitrogen metabolism,but suppress carbon metabolism．After adding inhibitor of nitrogen metabolism,carbon metabolism accelerate．content of total soluble sugar increased,especially under lowlight density．These result indicated that there exist the compete relationship between photosynthetic carbon an nitrogen metabolism．After adding inhibitor of carbon metabolism,nitrogen metabolism was suppressed after being enhanced,showed that there exist the coordinate relationship between carbon and nitrogen metabolism．nitrogen metabolism relied on carbon metabolism and was greatly influenced．...