Analysis of the P1 promoter in response to UV-B radiation in allelic variants of high-altitude maize

SEBASTIÁN P. RIUS; ERICH GROTEWOLD; PAULA CASATI

BMC PLANT BIOLOGY

BIOMED CENTRAL LTD

Lugar: Londres; Año: 2012 vol. 12 p. 92 - 92

1471-2229

BackgroundPlants living at high altitudes are typically exposed to elevated UV-B radiation, and harbormechanisms to prevent the induced damage, such as the accumulation of UV-absorbingcompounds. The maize R2R3-MYB transcription factor P1 controls the accumulation ofseveral UV-B absorbing phenolics by activating a subset of flavonoid biosynthetic genes inleaves of maize landraces adapted to high altitudes.ResultsHere, we studied the UV-B regulation of P1 in maize leaves of high altitude landraces, andwe investigated how UV-B regulates P1binding to the CHS promoter in both low and highaltitude lines. In addition, we analyzed whether the expansion in the P1 expression domainbetween these maize landraces and inbred lines is associated to changes in the molecularstructure of the proximal promoter, distal enhancer and first intron of P1. Finally, usingtransient expression experiments in protoplasts from various maize genotypes, weinvestigated whether the different expression patterns of P1 in the high altitude landracescould be attributed to trans- or cis-acting elements.ConclusionsTogether, our results demonstrate that, although differences in cis-acting elements existbetween the different lines under study, the different patterns of P1 expression are largely aconsequence of effects in trans.