RESUMO
The aphid is one of the most serious pests that causes damage to crops worldwide. Lectins from Araceae plant had been proved useful to control the aphid. Herein, the full-length cDNA of Monstera deliciosa agglutinin (mda) gene was cloned and then introduced into tobacco and the influence of the expression of mda in transgenic tobacco against peach-potato aphids (Myzus persicae) was investigated. Among 92 regenerated plants, 59 positive tobacco lines were obtained. Real-time PCR assays and aphid bioassay test revealed that there is a positive correlation between the expression level of mda and the inhibitory effect on peach-potato aphids. The average anti-pests ability of mda transgenic tobacco was 74%, which was higher than that of other reported lectins from Araceae plant. These results indicated that MDA is one of promising insect resistance proteins selected for the control of peach-potato aphids.
Assuntos
Aglutininas/genética , Afídeos/metabolismo , Araceae/genética , Nicotiana/genética , Sequência de Aminoácidos , Animais , Araceae/metabolismo , Bioensaio , Biotecnologia/métodos , Clonagem Molecular , DNA Complementar/metabolismo , Regulação da Expressão Gênica , Técnicas Genéticas , Vetores Genéticos , Dados de Sequência Molecular , Filogenia , Plantas Geneticamente Modificadas , RNA de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Homologia de Sequência de Aminoácidos , Fatores de Tempo , Nicotiana/metabolismoRESUMO
A new full-length cDNA encoding strictosidine synthase (designated as OjSTR, GenBank Accession No. 1087598), which catalyzes a committed step in camptothecin biosynthetic pathway, was isolated from young leaves of Ophiorrhiza japonica for the first time. OjSTR was 1,258 bp and contained a 1,062 bp open reading frame encoding a deduced protein of 353 amino acid residues. Sequence analyses showed that OjSTR had high homology with other STRs from some TIA-producing plants. Phylogenetic tree analysis showed that OjSTR had closest relationship with STR from O. pumila. Tissue expression pattern analysis revealed that OjSTR constitutively expressed in all the tested tissues at different levels, which was high in flower, moderate in leaf and root, low in stem. Expression profiles under plant defense signals such as methyl jasmonate and salicylic acid were investigated, and the results revealed that expression of OjSTR was all induced, implying that OjSTR was high elicitor responsive.
