玉米化感物质异羟肟酸的研究进展

介绍了异羟肟酸在玉米植株中的分布和玉米根系分泌物中异羟肟酸的分析方法．丁布(DIM-BOA)是玉米植株中含量最大的异羟肟酸．不同玉米品种之间异羟肟酸含量的差异很大．种子不含异羟肟酸；但萌发后其含量迅速增加，在萌芽几天后的幼苗植株其含量达最大值，随后逐渐下降；在玉米生长发育的不同时期，幼嫩叶片内异羟肟酸含量始终较高；地上部分异羟肟酸的浓度高于根系．植株异羟肟酸的浓度受生长环境条件影响显著，在紫外辐射、黑暗条件或水分胁迫下其含量明显增加．在各种禾谷类作物中，玉米根系分泌物内含异羟肟酸较高；铁的存在能显著增加玉米根系分泌物中异羟肟酸的含量．

Research advance in cyclic hydroxamic acids,main allelochemicals of Zea mays

The research advance in cyclic hydroxamic acids was reviewed in this paper.Cyclic hydroxamic acids are the important natural products of cereal crops.They and their respective derivatives are the constitutive compounds of a wide variety of gramineous plants and few dicot plants.They have structural diversity and different natural occurrences.Because of their phytotoxic properties,cyclic hydroxamic acids show a great variety of biological activities.They are the defensive agents against plant diseases,pests,nematodes and other plants.The distribution of cyclic hydroxamic acids in Zea mays and their variation in relation to the age were focused on in the paper.In Zea mays ,there are structural diversity of cyclic hydroxamic acids and related benzoxazolinones.DIMBOA (1,4 benzoxazin 3(4H) ones ) is the most abundant derivative in Zea mays .The content of cyclic hydroxamic acids is strongly cultivar dependent in Zea mays .Hydroxamic acids are not present in seeds.After germination,the level of DIMBOA increases,and the maximum level occurs in young seedlings a few days after germination.DIMBOA exists in all parts of plants,and its concentration is generally higher in shoots than in roots.In all stages,the young leaves of Zea mays have relatively high content of DIMBOA.The concentrations of these hydroxamic acids are highly dependent on environmental growth conditions.Under UV light and water deficiencies,the levels of hydroxamic acids in plant increase rapidly.Cyclic hydroxamic acids exuded by Zea mays root can be quantitatively analyzed by HPLC.Supplying iron can significantly increase the exudation of DIMBOA from Zea mays root.