VARIABILITY IN LIGHT GIBBERELLIN AND NITRATE REQUIREMENT OF ARABIDOPSIS-THALIANA SEEDS DUE TO HARVEST TIME AND CONDITIONS OF DRY STORAGE
VARIABILITY IN LIGHT GIBBERELLIN AND NITRATE REQUIREMENT OF ARABIDOPSIS-THALIANA SEEDS DUE TO HARVEST TIME AND CONDITIONS OF DRY STORAGE
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DOI：
10.1016/s0176-1617(11)80459-1
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发表时间：
1993-05-01
影响因子：
4.3
通讯作者：
KARSSEN, CM
中科院分区：
文献类型：
--
作者：
DERKX, MPM;KARSSEN, CM
不同季节收获的新鲜拟南芥种子对光（野生型）、赤霉素（GAs）（野生型、GA缺乏型、gal-2突变型）和硝酸盐的需求存在较大差异。一般来说，9 - 3月收获的种子对光的敏感性较高，4 - 6月收获的种子对光的敏感性明显较低。对气体的灵敏度几乎以平行的方式变化。这些敏感性的差异可归因于种子发育过程中的条件，如温度和硝酸盐的可用性。内源硝酸盐水平在不同种子批次之间差异很大（约为600倍），与10℃下15 min红光照射后的发芽率呈弱相关。此外，对硝态氮敏感性的差异可能是不同种子对光需求差异巨大的原因。其他未知因素也可能起作用。在萌发温度为10℃时，种子对气体和光照的敏感性明显高于在萌发温度为24℃时。种子干燥贮存后，休眠程度迅速下降。随着贮藏温度的升高，休眠的丧失速度加快；对光和气体的要求变得不那么严格了。对GAs的敏感性增加，最初只对白色荧光灯连续照射有反应的种子，在2摄氏度的干燥储存15个月后，对单个红光脉冲有反应。研究表明，拟南芥种子材料的大变异性和较高的后熟率阻碍了对其萌发和休眠的研究。
Freshly harvested seeds of Arabidopsis thaliana harvested in different seasons showed considerable variability in requirement for light (wild type), gibberellins (GAs)(wild type, GA deficient, gal-2 mutant) and nitrate. Generally, sensitivity to light was high in seed lots harvested between September and March and significantly lower in those harvested between April and June. Sensitivity to GAs varied in a nearly parallel way. These differences in sensitivity can be attributed to conditions during seed development, like temperature and nitrate availability. Endogenous nitrate levels varied enormously amongst seed lots (about a factor 600) and were weakly correlated to the germination capacity at 10-degrees-C after 15 min of red light irradiation. In addition, differences in sensitivity to nitrate may be responsible for the enormous differences in light requirement between seed lots. Other unknown factors may contribute as well. At a germination temperature of 10-degrees-C seeds were much more sensitive to GAs and light than at 24-degrees-C.The degree of dormancy rapidly declined upon dry storage of the seeds. Loss of dormancy was accelerated with increasing storage temperature; the requirements for light and GAs became less strict. Sensitivity to GAs increased and seeds that initially only responded to continuous irradiation with white fluorescent light, responded to a single red light pulse after 15 months of dry storage at 2-degrees-C.It is demonstrated that studies on germination and dormancy of A. thaliana are hampered by the large variability of seed material and the relatively high rate of after-ripening.