福建参薯类山药资源尿囊素含量的测定比较

运用高效液相色谱法测定福建参薯类山药资源的尿囊素含量，以检测比较不同参薯类山药资源的尿囊素含量。结果表明：在相同栽培条件下，不同产地山药的尿囊素含量存在一定的差异；采用YMC ODS-AQ色谱柱，尿囊素在0.3～2.1 μg间线性关系良好，回收率为96.4%(RSD＝2.4%)，精密度良好(RSD＝1.2%)，样品提取液在10 h内稳定(RSD＝2.0%)。该方法简便可靠，可作为山药质量控制的检测手段之一。     

福建参薯类山药资源尿囊素含量的测定比较

运用高效液相色谱法测定福建参薯类山药资源的尿囊素含量,以检测比较不同参薯类山药资源的尿囊素含量。结果表明:在相同栽培条件下,不同产地山药的尿囊素含量存在一定的差异;采用YMC ODS-AQ色谱柱,尿囊素在0.3～2.1μg间线性关系良好,回收率为96.4%(RSD=2.4%),精密度良好(RSD=1.2%),样品提取液在10 h内稳定(RSD=2.0%)。该方法简便可靠,可作为山药质量控制的检测手段之一。     

大豆植株中酰脲含量变化动态研究

试验对大豆植株各部位的酰脲含量进行了测定分析.结果表明,荚果和茎部酰脲含量高于叶片和叶柄,从苗期茎酰脲含量开始逐渐增加,至R5或R6期达到最高值;叶片酰脲含量在整个生育期中变化较小;叶柄酰脲含量呈先降低后增加的趋势,并于R6期达到最大值;荚果酰脲含量于R4或R5期达到最大值.大豆植株各部位尿囊酸与尿囊素的比例不同,叶片中尿囊酸含量与尿囊素含量相近,茎、叶柄、荚果尿囊酸含量显著高于尿囊素含量,其顺序为：茎＞荚果＞叶柄＞叶片.尿囊酸含量与酰脲含量呈显著正相关.     

赤豆种子萌发中酰脲累积动态及若干碳氮化合物对其形成的影响

赤豆种子萌发中,幼苗迅速合成酰脲,萌发第4d达到最大值.谷氨酰胺和甘氨酸促进尿囊素合成,谷氨酸和天冬酰胺对尿囊素合成影响较小.外源铵促进幼苗合成尿囊素.三羧酸循环的部分中间产物(特别是琥珀酸或延胡索酸)或高浓度的乙醛酸(6-10 mmol/L)不同程度地抑制幼苗的尿囊索合成.     

不同基因型大豆植株酰脲含量的动态规律

叶片和茎秆的酰脲含量除秣食豆外均呈现低-高-低的变化趋势。秣食豆叶片的酰脲含量呈现为“M”型曲线的变化趋势。秣食豆茎秆的酰脲含量呈现缓慢上升的趋势。荚皮酰脲含量东农42呈低-高-低变化,其他品种呈现为下降趋势。同一生育时期高蛋白品种东农42和黑农35各个时期酰脲含量都要高于高油品种东农46和垦丰9。同一生育时期营养器官之间的酰脲含量有较大差异。     

尿囊素与广增素对水稻幼苗生长及抗寒能力的影响

尿囊素（Ａｌ．）和广增素（ＧＺＳ）３００ｍｇ／Ｌ浸种可促进水稻幼苗生长，但对根／冠比影响不明显。在５～１５℃低温胁迫下３ｄ，Ａｌ．与ＧＺＳ均能提高稻叶ＳＯＤ活力，保护质膜结构，使丙二醛（ＭＤＡ）累积与电解质渗漏显著减少。同时能提高叶片相对含水量，并保持叶表保护结构基本完好。回温（２３～２６℃）７ｄ后，Ａｌ．与ＧＺＳ处理组稻苗存活率大大高于ＣＫ组。     

尿囊素对玉米幼苗根系生长及伤流液的影响

用尿囊素（Allantoin，All.）300mg/L和700mg/L喷淋一叶一心期的玉米超甜20号）幼苗，到四叶一心期对根系形态和伤流液进行测定。结果表明，尿囊素使一级根根数、最长根根长、根鲜重和根体积都比对照显著增加，整个根系显得强壮发达。同时，伤流液的流量、电导率、游离氨基酸总量及脯氨酸含量均明显高于对照，从而证明尿囊素确实促进了玉米幼苗根系的生长和对水分、矿质的吸收与同化能力，且尿囊素700mg/L的作用更优于300mg/L。     

Magnesium in barley plants on magnesium-deficient soils

Working with fused phosphate containing Mg, we have known some of the Mg-deficient areas in Shizuoka prefecture as a field problem. In these areas, crop plants develop visual hunger signs, resulting in restricted growth and reduced yield. The manurial effect of Mg-salt added or fused phosphate is remarkably excellent in these areas or soils.     

Silencing of OsXDH reveals the role of purine metabolism in dark tolerance in rice seedlings

Xanthine dehydrogenase(XDH) is a crucial enzyme involved in purine metabolism. To evaluate the effect of XDH deficiency on rice growth during dark treatment, wild type(WT) Nipponbare(Oryza sativa L.) and two independent transgenic lines with severe RNAi suppression(xdh3 and xdh4) were used in the present experiment. Under normal growth conditions, chlorophyll levels and biomass were indistinguishable between WT and the two RNAi transgenic lines, but XDH enzyme activity and ureide levels were suppressed in XDH RNAi transgenic lines. When XDH RNAi transgenic lines were subjected to dark treatment, chlorophyll content and biomass were significantly decreased, while O_2~–· production rate and malonaldehyde(MDA) were significantly increased compared to WT. The spraying test of exogenous allantoin raised chlorophyll content and biomass and reduced O_2~–· production rate and MDA in WT and both transgenic lines, and it also simultaneously reduced differences between RNAi and WT plants caused by XDH deficiency in growth potential and anti-oxidative capacity under dark treatment. These results suggested that fully functional purine metabolism plays an important role in reducing the sensitivity of rice seedlings to dark stress.