| A leucine to proline mutation in puroindoline b is frequently present in hard wheats from Northern Europe. Theoretical and Applied Genetics 100:1100-1107 |
Lillemo,M. and Morris,C.F.
Agricultural University of Norway and USDA-ARS Western Wheat Quality Lab |
| Endosperm hardness in wheat (Triticum aestivum L.) is determined by one major genetic factor, the Hardness (Ha) gene on the short arm of chromosome 5D. Grain hardness has previously been reported to result from either a failure to express puroindoline a (Pina-D1b), or a glycine to serine mutation at position 46 in puroindoline b (Pinb-D1b). In this study, which involves a large survey of 343 wheat genotypes of mostly
Northern European origin, we report two new mutations in puroindoline b associated
with hard endosperm. These were characterized as involving a leucine to proline
change at position 60 (Pinb-D1c), and a tryptophan to arginine change
at position 44 (Pinb-D1d), respectively. while the former seems to be
widely distributed in germplasm around the world, the latter was only found
in three winter wheats from Finland and Sweden. As discussed in the paper, the
three known mutations in puroindoline b can be considered "loss of function"
mutations (i.e. soft to hard), and structural analysis may serve to predict
that their dramatic effect of wheat grain texture is a result of reduced lipid-binding
ability.
|
 « Printable Version » |
|
|
