Identification of candidate genes for aphid resistance in upland cotton by QTL mapping and expression analysis
Qiushuang An,
Zhenyuan Pan,
Nurimanguli Aini,
Peng Han,
Yuanlong Wu,
Chunyuan You,
Xinhui Nie
Affiliations
Qiushuang An
Key Laboratory of Oasis Ecology Agricultural of Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi 832003, Xinjiang, China
Zhenyuan Pan
Key Laboratory of Oasis Ecology Agricultural of Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi 832003, Xinjiang, China
Nurimanguli Aini
Key Laboratory of Oasis Ecology Agricultural of Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi 832003, Xinjiang, China
Peng Han
Key Laboratory of Oasis Ecology Agricultural of Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi 832003, Xinjiang, China
Yuanlong Wu
Key Laboratory of Oasis Ecology Agricultural of Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi 832003, Xinjiang, China
Chunyuan You
Cotton Research Institute of the Shihezi Academy of Agriculture Science, Shihezi 832011, Xinjiang, China
Xinhui Nie
Key Laboratory of Oasis Ecology Agricultural of Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi 832003, Xinjiang, China; Corresponding author.
Lignin is one of the main components of cell walls and is essential for resistance to insect pests in plants. Cotton plants are damaged by aphid (Aphis gossypii) worldwide but resistant breeding is undeveloped due to scarce knowledge on resistance genes and the mechanism. This study reported a lignin biosynthesis-related gene identified in the F2 population derived from the cross between cotton cultivars Xinluzao 61 (resistant to aphid) and Xinluzao 50 (susceptible to aphid). A quantitative trait locus was mapped on chromosome D04 with a logarithm of odds (LOD) score of 5.99 and phenotypic effect of 27%. RNA-seq analysis of candidate intervals showed that the expression level of GH_D04G1418 was higher in the resistant cultivar than in the susceptible cultivar. This locus is close to AtLAC4 in the phylogenetic tree and contains a conserved laccase domain. Hence, it was designated GhLAC4-3. Silencing of GhLAC4-3 in Xinluzao 61 via virus-induced gene silencing (VIGS) resulted in decreased lignin content and increased susceptibility to aphids. These results suggest that GhLAC4-3 might enhance aphid resistance by regulating lignin biosynthesis in cotton.
