Chromosomal loci important for cotyledon opening under UV-B in Arabidopsis thaliana

BACKGROUND: Understanding of the genetic architecture of plant UV-B responses allows extensive targeted testing of candidate genes or regions, along with combinations of those genes, for placement in metabolic or signal transduction pathways. RESULTS: Composite interval mapping and single-marker analysis methods were used to identify significant loci for cotyledon opening under UV-B in four sets of recombinant inbred lines. In addition, loci important for canalization (stability) of cotyledon opening were detected in two mapping populations. One candidate locus contained the gene HY5. Mutant analysis demonstrated that HY5 was required for UV-B-specific cotyledon opening. CONCLUSIONS: Structured mapping populations provide key information on the degree of complexity in the genetic control of UV-B-induced cotyledon opening in Arabidopsis. The loci identified using quantitative trait analysis methods are useful for follow-up testing of candidate genes.

研究背景：阐明植物紫外线B（UV-B）响应的遗传调控架构，可针对候选基因、基因区域及其组合开展大规模靶向验证实验，以将其定位至代谢通路或信号转导通路中。研究结果：采用复合区间作图法（Composite Interval Mapping）与单标记分析法，在4组重组自交系（recombinant inbred lines）中筛选得到UV-B胁迫下子叶张开相关的显著遗传位点。此外，在2个作图群体中检测到对子叶张开发育稳态（稳定性）具有关键作用的位点。其中1个候选位点包含HY5基因。突变体分析实验证实，HY5是UV-B特异性诱导子叶张开所必需的基因。研究结论：结构化作图群体可为解析拟南芥UV-B诱导子叶张开的遗传调控复杂性提供关键信息。通过数量性状分析方法筛选得到的遗传位点，可用于后续候选基因的验证实验。