Reference "Response of rice to Al stress and identification of quantitative trait Loci for Al tolerance"

Reference ID

6898

Title

Response of rice to Al stress and identification of quantitative trait Loci for Al tolerance

Source

Plant & cell physiology, 2002, vol. 43, pp. 652-659

Authors (7)

Ma-J-F	Shen-R
Zhao-Z	Wissuwa-M
Takeuchi-Y	Ebitani-T
Yano-M

Abstract

Rice (Oryza sativa L.) shows the highest tolerance to Al toxicity among small-
grain cereal crops, however, the mechanisms and genetics responsible for its
high Al tolerance are not yet well understood. We investigated the response of
rice to Al stress using the japonica variety Koshihikari in comparison to the
indica variety Kasalath. Koshihikari showed higher tolerance at various Al
concentrations than Kasalath. The Al content in root apexes was less in
Koshihikari than in Kasalath, suggesting that exclusion mechanisms rather than
internal detoxification are acting in Koshihikari. Al-induced secretion of
citrate was observed in both Koshihikari and Kasalath, however, it is unlikely
to be the mechanism for Al tolerance because there was no significant difference
in the amount of citrate secreted between Koshihikari and Kasalath. Quantitative
trait loci (QTLs) for Al tolerance were mapped in a population of 183 backcross
inbred lines (BILs) derived from a cross of Koshihikari and Kasalath. Three
putative QTLs controlling Al tolerance were detected on chromosomes 1, 2 and 6.
Kasalath QTL alleles on chromosome 1 and 2 reduced Al tolerance but increased
tolerance on chromosome 6. The three QTLs explained about 27% of the phenotypic
variation in Al tolerance. The existence of QTLs for Al tolerance was confirmed
in substitution lines for corresponding chromosomal segments.