title: ACC oxidase and miRNA 159a, and their involvement in fresh fruit bunch yield (FFB) via sex ratio determination in oil palm.
abstract: Oil palm (Elaeis guineesis Jacq.) is the most productive oil-bearing crop, yielding more oil per area than any other oil-bearing crops. However, there are still efforts to improve oil palm yield, in order to serve consumer and manufacturer demand. Oil palm produces female and male inflorescences in an alternating cycle. So, high sex ratio (SR), the ratio of female inflorescences to the total inflorescences, is a favorable trait in term of increasing yields in oil palm. This study aims to understand the genetic control for SR related traits, such as fresh fruit bunch yield (FFB), by characterizing genes at FFB quantitative trait loci (QTLs) on linkage 10 (chromosome 6) and linkage 15 (chromosome 10). Published oil palm sequences at the FFB QTLs were used to develop gene-based and simple sequence repeat (SSR) markers. We used the multiple QTL analysis model (MQM) to characterize the relationship of new markers with the SR traits in the oil palm population. The RNA expression of the most linked QTL genes was also evaluated in various tissues of oil palm. We identified EgACCO1 (encoding aminocyclopropane carboxylate (ACC) oxidase) at chromosome 10 and EgmiR159a (microRNA 159a) at chromosome 6 to be the most linked QTL genes or determinants for FFB yield and/or female inflorescence number with a phenotype variance explained (PVE) from 10.4 to 15 % and suggest that these play the important roles in sex determination and differentiation in oil palm. The strongest expression of EgACCO1 and the predicted precursor of EgmiR159a was found in ovaries and, to a lesser extent, fruit development. In addition, highly normalized expression of EgmiR159a was found in female flowers. In summary, the QTL analysis and the RNA expression reveal that EgACCO1 and EgmiR159a are the potential genetic factors involved in female flower determination and hence would affect yield in oil palm. However, to clarify how these genetic factors regulate female flower determination, more investigation of their down regulation or target may be essential. Additionally, if more sex determination genes controlled by plant hormones are identified, it may possible to reveal a crosstalk of sex determination genes with hormones and environment factors.
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand. suthasinee.som@biotec.or.th.
authors.forename: Suthasinee
authors.initials: S
authors.lastname: Somyong
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand.
authors.forename: Supannee
authors.initials: S
authors.lastname: Poopear
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand.
authors.forename: Supreet Kaur
authors.initials: SK
authors.lastname: Sunner
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand.|Interdisciplinary Graduate Program in Genetic Engineering, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand.
authors.forename: Kitti
authors.initials: K
authors.lastname: Wanlayaporn
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand.
authors.forename: Nukoon
authors.initials: N
authors.lastname: Jomchai
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand.
authors.forename: Thippawan
authors.initials: T
authors.lastname: Yoocha
authors.affiliation: Department of Biotechnology, Faculty of Science and Technology, Thammasat University, Rangsit Campus, Klong Luang, Pathum Thani, 12121, Thailand.
authors.forename: Kittipat
authors.initials: K
authors.lastname: Ukoskit
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand.
authors.forename: Sithichoke
authors.initials: S
authors.lastname: Tangphatsornruang
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), 113 Thailand Science Park, Phaholyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand. somvong.tra@biotec.or.th.
authors.forename: Somvong
authors.initials: S
authors.lastname: Tragoonrung
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D028023:Arecaceae / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D005638:Fruit / Q000235:genetics / Q000254:growth & development*; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics*; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry; D010940:Plant Proteins / Q000235:genetics; D040641:Quantitative Trait Loci
chemical_list: D035683:MicroRNAs; D010938:Plant Oils; D010940:Plant Proteins; D000073878:Palm Oil; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase
keywords: ACC oxidase; Bunch yield; Oil palm; Sex determination; Sex ratio; miR159a