The Study On The Aluminum-tolerance Of Tibetan Wheat

The Al-tolerance of wheat is mainly controlled by genetic. ALMT1 is one of the most important genes that control Al-tolerance of wheat, which encodes a membrane protein to promote secretion of malic acid around wheat root tip. The malic acid can chalet the freely aluminum ion and hence reduce the aluminum toxicity of wheat. The upstream sequence of ALMT1 gene showed rich polymorphism, which can regulate the expression of ALMT1 gene to control the aluminum tolerance of wheat to a certain extent. For studying the genetic characteristics of Al-tolerance in Tibetan wheat, the upstream sequence types of ALMT1 gene, the relationship between the upstream sequence types and the Al-tolerance, as well as the ALMT1 gene were respectively analyzed in some Tibetan wheat lines.1. ALMT1 gene upstream sequence types in Tibetan wheatThe upstream sequence of ALMT1 gene was sequenced in 26 Tibetan wheat lines. A total of four different types,â… (â… '),â…¡,â…¤andâ…£, were found. Among them,16,3,5,1 and 1 wheat lines were typeâ… ,â… ',â…¡,â…¤andâ…£, respectively. The statistical analysis indicated that the Al-tolerant of wheat with upstream sequence Typeâ…¡is better than that of wheat with upstream sequence typeâ… orâ… `. There is no difference for aluminum tolerance between wheat with upstream sequence typeâ… andâ… `.2. The relationship between the aluminum tolerance and upstream sequence types of ALMT1 gene in two F2 populationsTo study the relationship between the aluminum tolerance and upstream sequence types of ALMT1 gene, two F2 populations of aluminum tolerance wheat As 1242 with upstream sequence type II with aluminum sensitive wheats As1302 and As1540 with upstream sequence type I, were developed, respectively. Based on the root re-growth lengths after aluminum treatment, it is found that the wheat lines with homologous upstream sequence type II and heteologous showed better aluminum tolerance than those of wheat lines with homologous upstream sequence type I in both of the F2 populations of As1242/As1302 and Asl242/Asl540, probably suggesting that that upstream sequence type II is related to the Al-tolerance in As 1242.3. Cloning and sequencing of ALMTl gene of Tibetan wheat As1540The ALMT1 gene of As 1540 was sequenced. The full-length of ALMT1 gene of Tibetan wheat As1540 is 3948bp in DNA length. The ALMT1 gene sequence of As1540 was very similar to the homologous gene of Al-sensitive wheat ES8 and the middle Al-tolerance wheat CS by 99.4% identity. The sequence difference among them are very minor, the difference between As 1540 and ET8 mainly existed in intron 3 and intron 4 by difference simple repeat sequences, and some SNPs replacement.