Phenotypic changes associated with RNA interference silencing of chalcone synthase in apple (Malus × domestica). (14th March 2013)

• Record Type: Journal Article
• Authors: Dare, Andrew P.; Tomes, Sumathi; Jones, Midori; McGhie, Tony K.; Stevenson, David E.; Johnson, Ross A.; Greenwood, David R.; Hellens, Roger P.
• Is Part Of: Plant journal. Volume 74:Number 3(2013:May)
• Page Start: 398
• Page End: 410
• Publication Date: 2013-03-14
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12140
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12140-abs-0001"> <title>Summary</title> <p>We have identified in apple (<italic>Malus</italic> × <italic>domestica</italic>) three chalcone synthase (<italic>CHS</italic>) genes. In order to understand the functional redundancy of this gene family RNA interference knockout lines were generated where all three of these genes were down‐regulated. These lines had no detectable anthocyanins and radically reduced concentrations of dihydrochalcones and flavonoids. Surprisingly, down‐regulation of <italic>CHS</italic> also led to major changes in plant development, resulting in plants with shortened internode lengths, smaller leaves and a greatly reduced growth rate. Microscopic analysis revealed that these phenotypic changes extended down to the cellular level, with <italic>CHS‐</italic>silenced lines showing aberrant cellular organisation in the leaves. Fruit collected from one <italic>CHS</italic>‐silenced line was smaller than the 'Royal Gala' controls, lacked flavonoids in the skin and flesh and also had changes in cell morphology. Auxin transport experiments showed increased rates of auxin transport in a <italic>CHS</italic>‐silenced line compared with the 'Royal Gala' control. As flavonoids are well known to be key modulators of auxin transport, we hypothesise that the removal of almost all flavonoids from the plant by <italic>CHS</italic> silencing creates a vastly altered environment for auxin transport to occur and results in the observed changes in growth and development.</p> </abstract>