Transcriptional and Characteristic Analysis of Expressed Sequence Tags from a Normalized Full-Length cDNA Library of Loquat Fruit at Different Developmental Stages

Loquat (Eriobotrya japonica Lindl.) fruit is popular for its delicious taste, rich nutrients and medical value. But the available genome resources on loquat fruit are very limited. In this study, an improved normalized full-length cDNA library construction was established mainly by the duplex-specific nuclease (DSN) normalization strategy and the SMART (TM) Kit. Sequencing results from randomly 8972 expressed sequence tags (ESTs) in loquat fruit cDNA library revealed 7451 unigenes with 70.3% non-redundancy rate and an average length 1.1 kb. Further, 2896 unigenes with potential full-length cDNAs were functionally classified and annotated by Gene Ontology (GO). Besides, some significant functional genes related to loquat fruit development and ripening were characterized and analyzed their expression patterns including three ethylene receptors (EjETR 1-3) and one ethylene transcription factor (EjETF), six cell wall expansin genes (EjEXPA 1-6) and the three key enzyme genes of carbohydrate metabolism (SS-S, SS-C, SPS). The establishment of normalized cDNA library with high ratio full-Length unigenes will make great contribution in discovering novel genes resource and promoting fruit quality improvement genetic engineering and molecular breeding of loquat. (C) 2018 Friends Science Publishers