Rauh L., Basten C., Buckler S.
USDA-ARS, Department of Genetics, North Carolina State University, Raleigh, NC 27695-7614, USA.
Theor Appl Genet. 2002 Apr;104(5):743-750. doi: 10.1007/s00122-001-0815-y. Epub 2002 Mar 13.
Nitrogen absorption and assimilation is variable among plants as a result of two factors: the source of nitrogen available and the genetic variation among species within the resulting nitrogen pathways. Several genes involved in nitrogen cycling have been identified, yet little is known about the genes that control quantitative responses to different nitrogen sources. With quantitative trait loci (QTL) mapping in Arabidopsis thaliana recombinant inbred lines (Columbia x Landsberg erecta) we have identified chromosomal regions controlling aerial mass, root mass, and root length when plants are grown in nitrate, ammonium, ammonium nitrate, or low nitrogen treatments. A total of 16 QTL ( P < 0.01) were identified among the nitrogen treatments. Most of the QTL were specific to a single treatment. The percentage additive genetic effects of significant QTL were as high as 17%. Five significant QTL corresponded to the locations of candidate genes associated with nitrogen assimilation, while a few QTL corresponded with candidate genes in the developmental pathways. Most QTL were not shared across treatments, suggesting that there is no optimal genotype for all nitrogen sources.
由于两个因素，植物对氮的吸收和同化存在差异：可用氮源以及氮循环途径中物种间的遗传变异。已经鉴定出了几个参与氮循环的基因，但对于控制对不同氮源定量反应的基因却知之甚少。通过在拟南芥重组自交系（哥伦比亚×兰茨贝格直立型）中进行数量性状基因座（QTL）定位，我们确定了在硝酸盐、铵盐、硝酸铵或低氮处理条件下生长时，控制地上部质量、根部质量和根长的染色体区域。在氮处理中总共鉴定出16个QTL（P < 0.01）。大多数QTL只针对单一处理。显著QTL的加性遗传效应百分比高达17%。五个显著QTL对应于与氮同化相关的候选基因位置，而少数QTL与发育途径中的候选基因相对应。大多数QTL在不同处理间不共享，这表明不存在适用于所有氮源的最优基因型。
