摘要
硝态氮(NO3--N)和铵态氮(NH4+-N)是植物吸收的两种主要氮素形态。由于植物对NO3-和NH4+吸收和同化的机制不同,导致叶片及果实中有机酸含量差异很大。本文阐述了不同形态氮素对植物叶片内有机酸合成的影响,指出供NO3-植物叶片中苹果酸、α-酮戊二酸及柠檬酸含量均显著高于供NH4+植物。番茄果实中苹果酸和柠檬酸是两种含量最多的有机酸,也是影响果实品质的重要因素;进一步分析了番茄果实发育过程中有机酸种类、含量及相关有机酸代谢酶活性的变化,探讨了不同形态氮素对番茄果实中苹果酸和柠檬酸含量以及氮代谢和有机酸代谢关键酶活性的影响。提出氮素形态可能对果实中有机酸含量有重要的调控作用,以期为农业生产中采用不同形态氮素调控果实有机酸代谢提供理论依据。
Nitrate （NO3^- -N） and ammonium （NH4＋-N） are the major sources of mineral nitrogen （N） taken up by higher plants. Differences in the uptake and assimilation of NO3 - and NH4 ＋ by tomato plants led to significant changes of organic acids in tomato leaves and fruits. It was reported that the contents of malate, α-ketoglutarate and citrate were significantly higher in NOz-- fed plant leaves than those in NH4 ＋- fed ones. Malate and citrate are the two quantitatively important organic acids in the fruit and take great effect on the fruit quality. The changes in the activities of the related enzymes of organic acid metabolism during tomato fruit ripening were further analyzed. Moreover, the effects of different N forms on the contents of malate and citrate and the activity of the key enzymes related to N metabolism and organic acid metabolism were discussed. It was suggested that the contents of organ- ic acids in the fruit might be regulated by N forms. This review may help to produce fruits with suitable organic acids content by N management practice.
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2009年第3期139-145,共7页
Journal of Nanjing Agricultural University
基金
国家自然科学基金资助项目(30600382)
土壤与农业可持续发展国家重点实验室开放基金(055131)
