Role of accumulated calcium in alleviating aluminum injury in wheat plants.
Aluminum (Al) sensitive wheat cultivar kalyansona was grown for 14 d in a range of Ca solution (125, 625, and 2500 μM) plus other nutrients without Al. At 14 d after Ca treatment, half of these plants were harvested (H1), and the rest of the plants were exposed to 100 μM Al for additional 6 d and harvested (H2). Severe Al injury was found only in the plants with the lowest supply of Ca before Al treatment. Aluminum concentration in the apoplastic fluid was very high at 125 μM Ca probably because the plasma membrane of some of the cells was destroyed due to the attack of 100 μM Al. Aluminum content in roots decreased with increasing supply of Ca before Al treatment. Calcium content decreased drastically at harvest (H2) in the plants with 100 μM Al. Under Al stress conditions, the plant responded to Al in different ways due to not only the different Ca supply but also the variation of Ca content in the plant tissues. Actually, the plants having the largest Ca content in the roots before Al treatment can receive less Al injury during Al treatment. To substantiate this idea, a companion study was conducted to investigate the effects of 2500 μM Ca supply during, before, and after 100 μM Al treatment on root growth. The results indicated clearly that exogenous Ca supply before Al treatment is able to alleviate Al injury but less effective than Ca supply during Al treatment.
Department of Crop Botany, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh ; Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia.
M Alamgir
MA
Hossain
Department of Crop Botany, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh ; Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia.
M
M
Ashrafuzzaman
Department of Crop Botany, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh ; Laboratory of Cell Technology, Gifu University, Japan.
A K M Zakir
AK
Hossain
Institute of Tropical Agriculture, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia.
Mohd Razi
MR
Ismail
Laboratory of Cell Technology, Gifu University, Japan.
H
H
Koyama
D000535:Aluminum / Q000633:toxicity*; D002118:Calcium / Q000008:administration & dosage*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development*; D014908:Triticum / Q000187:drug effects* / Q000254:growth & development*
D000535:Aluminum; D002118:Calcium