Main content area

Comparative studies of leaf surface chemical biosynthesis in different tobacco cultivars

Huang, Mingyue, Zhang, Hongying, Wang, Zhaojun, Niu, Dexin, Li, Yanhua, Cui, Hong
Acta physiologiae plantarum 2018 v.40 no.4 pp. 67
Aphidoidea, Nicotiana sylvestris, Nicotiana tabacum, Nicotiana tomentosiformis, biosynthesis, biotic stress, correlation, cultivars, diterpenoids, gas chromatography-mass spectrometry, gene expression regulation, genes, leaves, phylogeny, secretion, stress tolerance, tobacco, trichomes
To understand the differences in the biosynthesis of leaf surface chemicals and their influence on aphid preference for different tobacco cultivars (Nicotiana tabacum), we analyzed the secretory characteristics of glandular trichomes of four commercial cultivars, K326 (flue-cured), Beinhart 1000-1 (cigar), Basma YNOTBS1 (oriental), and Dabai 1 (burley), and their parental species, Nicotiana sylvestris and Nicotiana tomentosiformis. Trichome-type observation showed that K326 and N. sylvestris have three kinds of glandular trichomes (non-glandular, long stalked glandular, and short stalked glandular trichomes), whereas Beinhart 1000-1, Basma YNOTBS1, Dabai 1, and N. tomentosiformis had two kinds of glandular trichomes (long and short stalked glandular trichomes). The gas chromatography–mass spectrometry profiles of leaf exudates indicated that N. tomentosiformis synthesized only labdanoids; N. sylvestris, K326 and Dabai 1 synthesized only cembranoids; and Beinhart 1000-1 and Basma YNOTBS1 synthesized cembranoids and labdanoids. Gene expression pattern analysis revealed that the labdanoid synthesis-related genes NtABS and NtCPS2 were expressed in N. tomentosiformis, Beinhart 1000-1, and Basma YNOTBS1, whereas the cembranoid synthesis-related genes NtCYC and NtCYP71D16 were expressed in N. sylvestris and all four commercial cultivars. Evolutionary analysis indicated that NtCYC and NtCYP71D16 might be phylogenetically originated from N. sylvestris, whereas NtABS and NtCPS2 expressed in Basma YNOTBS1 and Beinhart 1000-1 might be derived from N. tomentosiformis. In addition, aphid attraction (number of aphids) was significantly and positively correlated with the total glandular secretion (r² = 0.9425, P ≤ 0.05), and it was significantly and positively correlated with amount of CBT-diol (r² = 0.9224; P ≤ 0.05). These results provide new insights into the biosynthesis of diterpenoids and biotic stress resistance in tobacco.