Molecular Cloning and Sequence Analysis of C4H Gene of Mangifera indica L.

Cinnamate-4-hydroxylase( C4H) is a key enzyme in phenylpropanoid pathway in plants. Its activity and abundance directly affect the biosynthesis of flavonoids and aromatic compounds. In this study,degenerate primers were designed according to previously reported C4 H gene sequences to clone C4H cDNA sequence with 3'and 5'RACE-PCR from mango( Mangifera indica L). The full-length cD NA of M. indica C4H is 1 680 bp long. Its open reading frame( ORF)is 1 518 bp,encoding a protein of 505 amino acids with a predicted molecular weight of 58. 08 kDa. The isoelectric point of the predicted protein is 9. 52. Functional prediction showed that this gene is mainly located in mitochondria. In addition,the tertiary structure of the protein was built using SWISS-MODEL,and the results showed that the protein has three possible conformations. Phylogenetic analysis based on C4H protein sequences revealed that M. indica has a close genetic relationship with olive( Canarium album) and cocoa( Theobroma cacao). By analyzing the expression level of C4H gene in three colored mango cultivars,we found that that the expression level of C4 H gene in Guifei( with red peel) was the highest,and that in Guiqi( with green peel) was the lowest. The results provide a theoretical basis for studying the molecular mechanism of anthocyanin biosynthesis and C4H's impact on the color of mango fruit.

Egg-associated secretions from the brown planthopper(Nilaparvata lugens)activate rice immune responses

The brown planthopper(BPH,Nilaparvata lugens)is a notorious sap-sucking insect pest that damages rice(Oryza sativa)plants throughout Asia.During BPH feeding,saliva enters rice plant tissues,whereas during oviposition egg-associated secretions(EAS)are deposited in damaged plant tissue.Dynamic changes in rice to planthopper salivary effectors have been widely reported.However,the effects of EAS from planthopper on rice immunity remains largely unexplored.In this study,we found that both infestation of rice by gravid BPH female adults and treatment with the EAS elicited a strong and rapid accumulation of jasmonic acid(JA),JA-isoleucine,and hydrogen peroxide in rice.EAS enhanced plant defenses not only in rice but also in tobacco,and these impaired the performance of BPH on rice,as well as the performance of aphids and whiteflies on tobacco.High-throughput proteome sequencing of EAS led to 110 proteins being identified and 53 proteins with 2 or more unique peptides being detected.Some proteins from BPH EAS were also found in the salivary proteome from herbivores,suggesting potential evolutionary conservation of effector functions across feeding and oviposition;however,others were only identified in EAS,and these are likely specifically related to oviposition.These findings point to novel proteins affecting interactions between planthoppers and rice during oviposition,providing an additional source of information for effector studies.