Transcriptional analysis of petal organogenesis in Gerbera hybrida

Abstract

Understanding of the molecular interplay, which determines early steps of flower formation has grown considerably during last years. In contrast, genetic actions responsible for how flower organs acquire their size and shape at later phases of organogenesis are still poorly understood. We have exploited the large and anatomically simple Gerbera (Gerbera hybrida var. Terra regina) ray flower petals to describe transcriptional changes during organogenesis. Gerbera 9 K cDNA microarray was utilized to profile gene expression at six different developmental stages of petal organogenesis, at the earliest stage expansion of petals is starting and at the latest stage petals have reached their final size and shape. Genes potentially participating in petal opening were identified based on the similarity in expression with a known marker gene. Our results showed characteristic sets of genes expressed during the cell division and cell expansion phases of petal development. Interestingly, there was a transition stage during which neither cell division nor cell expansion marker genes were abundantly expressed. Moreover, constitutive expression of late petal specific genes indicates that they participate in petal organogenesis throughout the development and they are not involved in stage specific switch points.

Plant biotechnology for deeper understanding, wider use and further development of agricultural and horticultural crops

“…Potentially useful genes for modification of fibre qualities for chemical industry have also been detected (Toikkanen et al 2007). Large-scale gene expression profiling has been used to study regulation of flower type identity (Laitinen et al 2006) and transcriptional changes during petal organogenesis (Laitinen et al 2007). Comparison of the developing ray and disc flower primordia uncovered the expression of many MADS box genes that respond to the radially patterned zones of the capitulum.…”

Nutritional and Proteomic Profiles in Developing Olive Inflorescence

“…Tetramers of MADS proteins are thought to determine floral organ identity (Jack, 2004;Taiz and Zeiger, 2010). The size and the shape of petals as well as of the rest whorls is genetically determined (Laitinen et al, 2007). However little data are available until now concerning flower proteomic (Dafny-Yelin et al, 2005;Moccia et al, 2009;Sun et al, 2009;Logacheva et al 2011;Zhu et al, 2011).…”

Preparation of a Xyloglucan Oligosaccharide Mixture from Tamarind Seed Gum and its Promotive Action on Flower Opening in Carnation Cultivars

“…However, these observations suggest that the action of XGO preparation may differ depending on the flower species as well as the cultivar. Therefore it will be of interest to test the action of the XGO preparation broadly in different ornamental flowers, such as sandarsonia, Alstroemeria and Gerbera hybrida, as mentioned in the Introduction, since the involvement of xyloglucan metabolism in flower opening has been suggested in these flowers (Breeze et al, 2004;Laitinen et al, 2007;O'Donoghue et al, 2002).…”

“…Breeze et al (2004) showed that an XTH gene was up-regulated in developing petals of opening Alstroemeria flowers. Laitinen et al (2007) showed that Gerbera hybrida had several XTH genes and their expression pattern during the development of ray flowers differed; some genes were up-regulated in the early stage and down-regulated in the late stage of petal development, and others vice versa. Recently, Harada et al (2011) cloned four cDNAs for XTH (DcXTH1-DcXTH4) from petals of opening carnation (Dianthus caryophyllus L.) flowers and examined the expression of their corresponding genes in floral and vegetative tissues of carnation plants with opening flowers, revealing that DcXTH2 and DcXTH3 are associated with petal growth and development during carnation flower opening.…”