Cloning of three genes involved in the flavonoid metabolic pathway and their expression during insect resistance in Pinus massoniana Lamb.

Abstract

Pinus massoniana Lamb. is an important timber and turpentine-producing tree species in China. Dendrolimus punctatus and Dasychira axutha are leaf-eating pests that have harmful effects on P. massoniana production. Few studies have focused on the molecular mechanisms underlying pest resistance in P. massoniana. Based on sequencing analysis of the transcriptomes of insect-resistant P. massoniana, three key genes involved in the flavonoid metabolic pathway were identified in the present study (PmF3H, PmF3'5'H, and PmC4H). Structural domain analysis showed that the PmF3H gene contains typical binding sites for the 2OG-Fe (II) oxygenase superfamily, while PmF3'5'H and PmC4H both contain the cytochrome P450 structural domain, which is specific for P450 enzymes. Phylogenetic analysis showed that each of the three P. massoniana genes, and the homologous genes in gymnosperms, clustered into a group. Expression of these three genes was highest in the stems, and was higher in the insect-resistant P. massoniana varieties than in the controls. The extent of the increased expression in the insect-resistant P. massoniana varieties indicated that these three genes are involved in defense mechanisms against pests in this species. In the insect-resistant varieties, rapid induction of PmF3H increased the levels of PmF3'5'H and PmC4H expression. The enhanced anti-pest capability of the insect-resistant varieties could be related to temperature and humidity. In addition, these results suggest that these three genes maycontribute to the change in flower color during female cone development.

Flavonoid Accumulation Plays an Important Role in the Rust Resistance of Malus Plant Leaves

“…When confronted with abiotic stress, the flavonoid composition in plant tissues and organs changes in response to possible cell damage, which induces changes in the coloring of visible parts ( Cantín et al, 2007 ; Zhang et al, 2014 ). For example, plants often produce pigments around wounds, pathogen infection sites, insect piercing and feeding sites, and physical injuries, with various color responses observed among different plant varieties and even in different tissues ( Petre et al, 2012 ; Dubovskiy et al, 2013 ; Fogelman et al, 2015 ; Yang et al, 2016 ). However, the role of these different color phenotypes caused by infection as well as the function of flavonoid composition changes and the mechanisms underlying the regulation of related gene transcription and their relationship to the metabolic pathways are not clear.…”

Identification and molecular characterization of flavonoid biosynthetic genes and their expression analysis in wheatgrass (Triticum aestivum L.) during leaf rust infection

“…The phenotypic appearance of yellow/brown spots on different plant organs as well as on leaf surfaces is due to the accumulation of avonoids which potentially depicts environmental stress or exposure to pathogen infection. When confronted with various stresses plants often produce pigments in response as an early symptom which can be utilized for diagnosis and prevention strategies (Mierziak et al, 2014;Yang et al, 2016). However, the role of these different phenotypic pigmentation patterns on different plant parts is sundry and the underlying mechanism at the molecular level is mostly unexplored.…”

Transcriptome Analysis of Response to Aluminum Stress in Pinus massoniana

“…P. massoniana, one of the most important coniferous species in southern China, is widely cultivated with strong adaptability, rapid growth, and good stress tolerance [20,21]. P. massoniana has an important position in forestry production.…”