title: Identification of Appropriate Reference Genes for Normalization of miRNA Expression in Grafted Watermelon Plants under Different Nutrient Stresses.
abstract: Watermelon (Citrullus lanatus) is a globally important crop belonging to the family Cucurbitaceae. The grafting technique is commonly used to improve its tolerance to stress, as well as to enhance its nutrient uptake and utilization. It is believed that miRNA is most likely involved in its nutrient-starvation response as a graft-transportable signal. The quantitative real-time reverse transcriptase polymerase chain reaction is the preferred method for miRNA functional analysis, in which reliable reference genes for normalization are crucial to ensure the accuracy. The purpose of this study was to select appropriate reference genes in scion (watermelon) and rootstocks (squash and bottle gourd) of grafted watermelon plants under normal growth conditions and nutrient stresses (nitrogen and phosphorus starvation). Under nutrient starvation, geNorm identified miR167c and miR167f as two most stable genes in both watermelon leaves and squash roots. miR166b was recommended by both geNorm and NormFinder as the best reference in bottle gourd roots under nutrient limitation. Expression of a new Cucurbitaceae miRNA, miR85, was used to validate the reliability of candidate reference genes under nutrient starvation. Moreover, by comparing several target genes expression in qRT-PCR analysis with those in RNA-seq data, miR166b and miR167c were proved to be the most suitable reference genes to normalize miRNA expression under normal growth condition in scion and rootstock tissues, respectively. This study represents the first comprehensive survey of the stability of miRNA reference genes in Cucurbitaceae and provides valuable information for investigating more accurate miRNA expression involving grafted watermelon plants.
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, Zhejiang, P. R. China.
authors.forename: Weifang
authors.initials: W
authors.lastname: Wu
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, Zhejiang, P. R. China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Deng
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, Zhejiang, P. R. China.
authors.forename: Pibiao
authors.initials: P
authors.lastname: Shi
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, Zhejiang, P. R. China.|Key laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, Zhejiang, P. R. China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, Zejiang, P. R. China.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Yang
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, Zhejiang, P. R. China.|Key laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, Zhejiang, P. R. China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, Zejiang, P. R. China.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou, Zhejiang, P. R. China.|Key laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, Hangzhou, Zhejiang, P. R. China.|Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Hangzhou, Zejiang, P. R. China.
authors.forename: Mingfang
authors.initials: M
authors.lastname: Zhang
mesh_terms: D029773:Citrullus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000302:isolation & purification / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological
chemical_list: D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant