Review

Molecular basis of powdery mildew resistance in wheat (Triticum aestivum L.)

Jishan Niu¹ and Dexian He²*

¹National Centre of Engineering and Technological Research for Wheat, Henan

Agricultural University, Zhengzhou 450002, Henan, P. R. China.

²College of Agriculture, Henan Agricultural University, Zhengzhou 450002, Henan, P. R. China.

*Corresponding author. E-mail: hedexian@hotmail.com.

Abbreviations: AFLP, amplified fragment length polymorphism; AR, acquired resistance; Bgh, Blumeria graminis f. sp. hordei; Bgt, Blumeria graminis f. sp. tritici; BSA, bulked segregating analysis; CC, coiled-coil; CTR, constitutive triple response; DDRT-PCR, differential display reverse transcription-PCR; EDR1, enhanced disease resistance 1; EST, expression sequence tag; HR: hypersensitive response; IR: induced resistance; ISR: induced systemic resistance; JA, jasmonic acid; JRP, jasmonate-regulated protein; LAR, local acquired resistance; LRR, leucine-rich repeat; MAPK, mitogen-activated protein kinase; MeJA, methyl jasmonate; NBS, nucleotide-binding site; NLS, nuclear localization motif; NPR1, nonexpresser of PR gene l; PR, pathogenesis-related; R, resistance; RFLP, restriction fragment length polymorphism; RGA, resistance gene analog; RNAi, RNA interference; SA, salicylic acid; SAR, systemic acquired resistance; SSH, suppression subtractive hybridization; WLRK, wheat leaf rust kinase.

Accepted 19 December, 2008

Powdery mildew is one of the most destructive foliar diseases of wheat worldwide. Improving wheat resistance to Blumeria graminis f. sp. tritici (Bgt) via modern bio-techniques to understand the molecular basis of powdery mildew resistance is very important. Powdery mildew resistance gene Pm3b was has been isolated, and its alleles were have been studied. Some other genes associated with resistance against Bgt were also studied. Wheat TaMLO genes, similar to barley powdery mildew resistance regulating gene MLO, were cloned by the authors. TaEDR1, similar to the EDR1 gene associated with powdery mildew resistance in Arabidopsis thaliana, was also cloned. It has been demonstrated that TaLRK, Ta-JA2, TaPR-1, TaPR-2 and TaPR-5 genes play positive roles in powdery mildew resistance. However, no systemic signal pathways of powdery mildew resistance have been reported as yet. Therefore, this review is aimed particularly at the molecular basis of powdery mildew resistance in wheat.

Key words: Wheat, powdery mildew, resistance, molecular biology, signal pathway.