A Preliminary Study On The Regulation Mechanism Of Flowering In Prunus Mume Sieb. Et Zucc.

Prunus mume Sieb. Et Zucc. originated from China, plays an important role in the Chineselandscape art and flower culture. For the people’s enjoyment, Prunus mume has become one of themost popular flowers in China. The phenomen of the short flowering period in outdoor plantingPrunus mume, however, brought a great regretting for the general public. So it is very important tostudy the regulation mechanism of Prunus mume flowering. The physiological and biochemicalindexes of Prunus mume were determined and analyzed after plant growth regulators’ treatment,including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and the phytohormone;The important homologous gene on flowering, LFY, was cloned through the technique of PCR; Thetemporal and spatial expression of PmLFY,PmTFL1was studied through the Real time RT-PCR. Theregulation mechanism of flowering in Prunus mume was discussed from the point of plant physiologyand molecular biology. The results were as follows:1. The physiological and biochemical indexes of Prunus mume were determined and analyzedafter plant growth regulators’ treatment. The comprehensive evaluation using Membership functionsshowed that the optimized treatment for improving flowering earlier were GA2(1000ppm GA3) andGA3(2000ppm GA3), while that for delaying flowering were PP1(500ppm PP333) and PP2(1000ppmPP333). The treatment in October was more advantageous to Prunus mume flowering regulation thanthat in January.2. The content of endogenous hormones (ZR, GA3, IAA and ABA) were measured using anenzyme-linked immunosorbent assay (ELISA) method. The exogenous GA3treatment can improvethe contents of ZR, GA3, and IAA and the ratio of GA3/ABA, and decrease the content of ABA.However, the exogenous PP333treatment can decrease the contents of ZR, GA3, and IAA and the ratioof GA3/ABA, but increase the content of ABA.3. There were1230bp of PmLFY from the initiation codon to the termination codon and encoding409amino acids. The cDNA sequence homology and amino acid sequence homology was similarwith the other15plants (85.59%). The phylogenetic tree showed PmLFY was closest to apricot,fllowed by flowering peach, but far from litchi gene.4. To determine the special-temporal expression pattern of PmLFY and PmTFL1under differentplant growth regulators’ treatments, fluorescence Real Time RT-PCR techniques were applied. Theresults showed that in different position of ‘Jiang Mei’, the highest expression of PmLFY was noticedin the fruit, followed by bud, stem and flower, and lowest expression was in leaves. While the highestexpression of PmTFL1was in the stem, followed by flower, leaves and buds, and the lowestexpression was in fruit. Exogenous GA3treatment promoted PmLFY expression, inhibited PmTFL1expression in flower buds of ‘Jiang Mei’. However exogenous PP333treatment promoted PmTFL1expression and inhibited PmLFY expression.