Excited-state intramolecular proton transfer with and without the assistance of vibronic-transition-induced skeletal deformation in phenol-quinoline.

The excited-state intramolecular proton transfer (ESIPT) reaction of two phenol-quinoline molecules (namely PQ-1 and PQ-2) were investigated using time-dependent density functional theory. The five-(six-) membered-ring carbocycle between the phenol and quinolone moieties in PQ-1 (PQ-2) actually causes a relatively loose (tight) hydrogen bond, which results in a small-barrier (barrier-less) on an excited-state potential energy surface with a slow (fast) ESIPT process with (without) involving the skeletal deformation motion up to the electronic excitation. The skeletal deformation motion that is induced from the largest vibronic excitation with low frequency can assist in decreasing the donor-acceptor distance and lowering the reaction barrier in the excited-state potential energy surface, and thus effectively enhance the ESIPT reaction for PQ-1. The Franck-Condon simulation indicated that the low-frequency mode with vibronic excitation 0 → 1' is an original source of the skeletal deformation vibration. The present simulation presents physical insights for phenol-quinoline molecules in which relatively tight or loose hydrogen bonds can influence the ESIPT reaction process with and without the assistance of the skeletal deformation motion.

Genetic analysis and gene mapping of the glabrous leaf and hull mutant glr3 in rice (Oryza sativa L.).

We obtained a glabrous leaf and hull mutant from a population of radiation mutagenesis of an indica rice cultivar R401. The mutant produced smooth leaves and hairless glumes under normal growth conditions. An F2 population was developed from a cross between a japonica cultivar Nipponbare and the glabrous leaf and hull mutant. By investigating the performance of the F2 population, we found that the mutant phenotype was controlled by a single recessive gene, temporarily designated GLR3. Bulked segregant analysis (BSA) based on the F2 mapping population revealed that GLR3 is located on chromosome 6. By analyzing 417 typical glabrous leaf F2 plants using molecular markers, GLR3 was mapped to a 0.2 cM interval between InDel markers ID27101 and ID27199, and the physical distance between the two markers is 98 kb. Thus we have mapped the gene GLR3, and our work will provide basis for future mechanistic analysis of GLR3 function.