Singh Sharad K, Shukla Ashutosh K, Dhawan Om P, Shasany Ajit K
Genetics and Plant Breeding Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, Uttar Pradesh, India; Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, Uttar Pradesh, India.
Biotechnology Division, CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, Uttar Pradesh, India.
PLoS One. 2014 Jun 30;9(6):e101272. doi: 10.1371/journal.pone.0101272. eCollection 2014.
The involvement of PISTILLATA (PI) and APETALA (AP) transcription factors in the development of floral organs has previously been elucidated but little is known about their upstream regulation. In this investigation, two novel mutants generated in Papaver somniferum were analyzed--one with partially petaloid sepals and another having sepaloid petals. Progeny from reciprocal crosses of respective mutant parent genotypes showed a good fit to the monogenic Mendelian inheritance model, indicating that the mutant traits are likely controlled by the single, recessive nuclear genes named "Pps-1" and "OM" in the partially petaloid sepal and sepaloid petal phenotypes, respectively. Both paralogs of PISTILLATA (PapsPI-1 and PapsPI-3) were obtained from the sepals and petals of P. somniferum. Ectopic expression of PapsPI-1 in tobacco resulted in a partially petaloid sepal phenotype at a low frequency. Upregulation of PapsPI-1 and PapsAP3-1 in the petal and the petal part of partially petaloid sepal mutant and down-regulation of the same in sepaloid petal mutant indicates a differential pattern of regulation for flowering-related genes in various whorls. Similarly, it was found that the recessive mutation OM in sepaloid petal mutant downregulates PapsPI-1 and PapsAP3-1 transcripts. The recessive nature of the mutations was confirmed by the segregation ratios obtained in this analysis.
PISTILLATA（PI）和APETALA（AP）转录因子在花器官发育中的作用此前已得到阐明，但对其上游调控却知之甚少。在本研究中，分析了罂粟中产生的两个新突变体——一个具有部分花瓣状萼片，另一个具有萼片状花瓣。各突变亲本基因型正反交的后代与单基因孟德尔遗传模型拟合良好，表明突变性状可能分别由部分花瓣状萼片和萼片状花瓣表型中名为“Pps - 1”和“OM”的单个隐性核基因控制。从罂粟的萼片和花瓣中获得了PISTILLATA的两个旁系同源基因（PapsPI - 1和PapsPI - 3）。PapsPI - 1在烟草中的异位表达导致低频率出现部分花瓣状萼片表型。在部分花瓣状萼片突变体的花瓣和花瓣部分中PapsPI - 1和PapsAP3 - 1上调，而在萼片状花瓣突变体中则下调，这表明不同轮中与开花相关基因的调控模式存在差异。同样，发现萼片状花瓣突变体中的隐性突变OM下调了PapsPI - 1和PapsAP3 - 1转录本。通过本分析中获得的分离比证实了突变的隐性性质。
