The Wheat Lr67 Gene from the Sugar Transport Protein 13 Family Confers Multipathogen Resistance in Barley

• Published in: Plant physiology (Bethesda) 2019-04, Vol.179 (4), p.1285-1297
• Main Authors: Milne, Ricky J, Dibley, Katherine E, Schnippenkoetter, Wendelin, Mascher, Martin, Lui, Andy C W, Wang, Lanxiang, Lo, Clive, Ashton, Anthony R, Ryan, Peter R, Lagudah, Evans S
• Format: Article
• Language: English
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.18.00945

Fungal pathogens are a major constraint to global crop production; hence, plant genes encoding pathogen resistance are important tools for combating disease. A few resistance genes identified to date provide partial, durable resistance to multiple pathogens and the wheat ( ) Lr67 hexose transporter variant (Lr67res) fits into this category. Two amino acids differ between the wild-type and resistant alleles - G144R and V387L. Exome sequence data from 267 barley ( ) landraces and wild accessions was screened and neither of the Lr67res mutations was detected. The barley ortholog of Lr67, HvSTP13, was functionally characterized in yeast as a high affinity hexose transporter. The G144R mutation was introduced into HvSTP13 and abolished Glc uptake, whereas the V387L mutation reduced Glc uptake by ∼ 50%. Glc transport by HvSTP13 heterologously expressed in yeast was reduced when coexpressed with Stable transgenic barley lines exhibited seedling resistance to the barley-specific pathogens and f. sp. , which cause leaf rust and powdery mildew, respectively. Barley plants expressing exhibited early senescence and higher pathogenesis-related ( ) gene expression. Unlike previous observations implicating flavonoids in the resistance of transgenic sorghum ( ) expressing , another wheat multipathogen resistance gene, barley flavonoids are unlikely to have a role in Lr67res-mediated resistance. Similar to observations made in yeast, Lr67res reduced Glc uptake These results confirm that the pathway by which confers resistance to fungal pathogens is conserved between wheat and barley.