BGS 188, Aluminum tolerance, Alp1

Aluminum tolerance (4, 17).
Aluminum tolerance = Alp (15).
pH tolerance = Pht (18).
Aluminum tolerance = Alt (14).
Hordeum vulgare Al-activated citrate transporter 1 = HvAACT1 (7).

Incomplete dominant with inheritance pattern dependent on Al concentration (15, 16).
Location in chromosome 4HL (13, 18); Alp1.a is about 25 cM from the Kap1 (Hooded awn 1) locus (18); Alp1.a is 2.1 cM proximal to the marker Xbcd1117 and 2.1 cM distal to the markers Xwg464 and Xcdo1395 (19); the Alp1 locus is flanked by SSR markers Bmag353 and HVM68 (21); Alp1.a is flanked by microsatellite markers Bmac310 and Bmag353 (9); the 4H QTL for Al-tolerance is 0.8 cM from DArT marker bPb-6949 (3).

Better performance in acid or aluminum-toxic soils was observed among spring (10, 11, 17) and winter (4, 15, 16) barley cultivars. An association between root and shoot yields in greenhouse studies and grain yield in field studies was reported (16). Recommended screening conditions in nutrient solutions with 4 ppm aluminum (Al) and adjusted twice daily to pH 4.8 (5, 15). Retarded root elongation was observed in 4 to 5 days with roots thickened and more branched. Al-tolerant cultivars tended to raise the pH while the opposite tend was reported for Al-sensitive cultivars (5). Aluminum sensitivity of cultivars was determined by staining seedling roots after aluminum treatment with a hematoxylin staining solution (12). An Al-tolerant cultivar secreted citrate from the roots in response to Al treatment (9, 22) The differential acid soil response caused by alleles at the Alp1 locus was associated with the HvAACT1 (Hordeum vulgare Al-activated citrate transporter 1) gene (7; 21). Increased expression of the HvAACT1 gene in East Asian cultivars was associated with the presence of a 1023-bp transposable-element like insertion in the 5’ untranslated region (6).

Natural occurrence in Dayton (PI 539129) from Composite Cross X (CIho 6625) (4, 15) and in Charlottetown 80 (CIho 2732) (10, 11).

Alp1.a in Dayton (PI 539129) (15); Alp1.a in Murasakimochi (6, 9); Alp1.a in Svanhals (NGB 1482, PI 5474) (2); Alp1.a in Honen (PI 307495) (21); Al-tolerance is present in Tibetan wild barley at the Alp1 locus (3); Alp1.a in Cevada BR2 (1); a new allele (Alp1.c) at the Alp1 locus was identified in Chinese barley CXHKSL (8).

Alp1.a in Dayton; Alp1.a in Svanhals; Alp1.a in Murasakimochi; Alp1.c in CXHKSL.
References:

1. Bian, M., X. Jin, S. Broughton, X.Q. Zhang, G. Zhou, M. Zhou, G. Zhang, D. Sun, and C. Li. 2015. A new allele of acid soil tolerance gene from a malting barley variety. BMC Genet. 16:92.
2. Bian, M., I. Waters, S. Broughton, X.Q. Zhang, M. Zhou, R. Lance, D. Sun, and C. Li. 2013. Development of gene-specific markers for acid soil/aluminium tolerance in barley (Hordeum vulgare L.). Mol Breed. 32:155-164.
3. Cai, S., D. Wu, Z. Jabreen, Y. Huang, Y. Huang, and G. Zhang. 2013. Genome-wide association analysis of aluminium tolerance in cultivated and Tibetan wild barley. PLoS ONE 8(7): e69776.
4. Foy, C.D., W.H. Armiger, L.W. Briggle, and D.A. Reid. 1965. Differential aluminum tolerance of wheat and barley varieties in acid soils. Agron. J. 57:413-417.
5. Foy, C.D., A.L. Fleming, G.R. Burns, and W.H. Armiger. 1967. Characterization of differential aluminum tolerance among varieties of wheat and barley. Proc. Soil Sci. Soc. Amer. 31:513-521.
6. Fujii, M., K. Yokosho, N. Yamaji, D. Saisho, M. Yamane, H. Takahashi, et al. 2012. Acquisition of aluminium tolerance by modification of a single gene in barley. Nat. Commun. 3:713.
7. Furukawa, J., N. Yamaji, H. Wang, N. Mitani, Y. Murata, K. Sato, M. Katsuhara, K. Takeda, and J.F. Mal. 2007. An aluminum-activated citrate transporter in barley. Plant Cell Physiol. 48:1081-1091.
8. Ma, Y., C. Li, P.R. Ryan, S. Shabala, J. You, J. Liu, C. Liu, and M. Zhou. 2016. A new allele for aluminium tolerance gene in barley (Hordeum vulgare L.). BMC Genomics 17:186.
9. Ma, J.F., S. Nagao, K. Sato, H. Ito, J. Furukawa, and K. Takeda. 2004. Molecular mapping of a gene responsible for Al-activated secretion of citrate in barley. J. Exp. Bot. 55:1335-1341.
10. MacLean, A.A., and T.C. Chiasson. 1966. Differential performance of two barley varieties to varying aluminum concentration. Can. J. Soil Sci. 46:147-153.
11. MacLeod, L.B., and L.P. Jackson. 1967. Aluminum tolerance of two barley varieties in nutrient solution, peat, and soil culture. Agron. J. 59:359-363.
12. Minella, E., and M.E. Sorrells. 1992. Aluminum tolerance in barley: genetic relationships among genotypes of diverse origin. Crop Sci. 40:329-337.
13. Minella, E., and M.E. Sorrells. 1997. Inheritance and chromosome location of Alp, a gene controlling aluminum tolerance in “Dayton” barley. Plant Breed. 116:465-469.
14. Raman, H,. J.S. Moroni, K. Sato, B. Read, and B.J. Scott. 2002. Identification of AFLP and microsatellite markers linked with an aluminium tolerance gene in barley (Hordeum vulgare L.). Theor. Appl. Genet. 105:458-464,
15. Reid, D.A. 1970. Genetic control of reaction to aluminum in winter barley. p. 409-413. In R.A. Nilan (ed.) Barley Genetics II. Proc. Second Int. Barley Genet. Symp., Pullman, WA, 1969. Washington State Univ. Press, Pullman.
16. Reid, D.A., G.D. Jones, W.H. Armiger, C.D. Foy, E.J. Koch, and T.M. Starling. 1969. Differential aluminum tolerance of winter barley varieties and selections in associated greenhouse and field experiments. Agron. J. 61:218-222.
17. Stølen, O. 1965. Investigations on the tolerance of barley varieties to high hydrogen-ion concentrations in soil. p. 81-107 in Royal Vet. Agr. Coll. Yearbook, Copenhagen,
18. Stølen, O., and S. Anderson. 1978. Inheritance of tolerance to low soil pH in barley. Hereditas 88:101-105.
19. Tang, Y., M.E. Sorrells, L.V. Kochian, and D.F. Garvin. 2000. Identification of RFLP markers linked to the barley aluminum tolerance gene Alp. Crop Sci. 40:778-782.
20. Wang, J., H. Raman, M. Zhou, P.R. Ryan, E. Delhaize, D.M. Hebb, N. Coombes, and N. Mendham. 2007. High resolution mapping of the Alp locus and identification of a candidate gene HvMATE controlling aluminium tolerance in barley (Hordeum vulgare L.). Theor. Appl. Genet. 115:265-276.
21. Wang, J., H. Raman, B. Read, M. Zhou, N. Mendham, and S. Venkatanagappa. 2006. Validation of an Alt locus for aluminium tolerance scored with eriochrome cyanine R staining method in barley cultivar Honen (Hordeum vulgare L.). Australian J. Agric. Res. 57:113-118.
22. Zhou, G., E. Delhaize, M. Zhou, and P.R. Ryan. 2013. The barley MATE gene, HvAACT1, increases citrate efflux and Al(3+) tolerance when expressed in wheat and barley. Ann. Bot. 112:603-612.

J.D. Franckowiak. 2017. Barley Genet. Newsl. 47:98-100.