Classification of fruit trichomes in cucumber and effects of plant hormones on type II fruit trichome development

Abstract

Cucumber fruit trichomes could be classified into eight types; all of them are multicellular with complex and different developmental processes as compared with unicellular trichomes in other plants. The fruit trichomes or fruit spines of cucumber, Cucumis sativus L., are highly specialized structures originating from epidermal cells with diverse morphology, which grow perpendicular to the fruit surface. To understand the underlying molecular mechanisms of fruit trichome development, in this study, we conducted morphological characterization and classification of cucumber fruit trichomes and their developmental processes. We examined the fruit trichomes among 200 cucumber varieties, which could be classified into eight morphologically distinct types (I-VIII). Investigation of the organogenesis of the eight types of trichomes revealed two main developmental patterns. The development of glandular trichomes had multiple stages including initiation and expansion of the trichome precursor cell protuberating out of the epidermal surface, followed by periclinal bipartition to two cells (top and bottom) which later formed the head region and the stalk, respectively, through subsequent cell divisions. The non-glandular trichome development started with the expansion of the precursor cell perpendicularly to the epidermal plane followed by cell periclinal division to form a stalk comprising of some rectangle cells and a pointed apex cell. The base cell then started anticlinal bipartition to two cells, which then underwent many cell divisions to form a multicellular spherical structure. In addition, phytohormones as environmental cues were closely related to trichome development. We found that GA and BAP were capable of increasing trichome number per fruit with distinct effects under different concentrations.

Transcriptome Analysis of Elm (Ulmus pumila) Fruit to Identify Phytonutrients Associated Genes and Pathways

“…Several plant hormones are reported to control the regulation of fruit development and ripening, such as the gaseous hormone ethylene, abscisic acid (ABA), and gibberellin [49][50][51]. In this study, 59 upregulated genes were annotated in the "abscisic acid-activated signaling pathway" (GO:0009738), including Arabidopsis seed storage protein CRA1 (Cluster-6074.12833, L 2 fc = 19.335) and seed maturation-associated ABA-responsive element binding protein AREB3 (Cluster-6074.15351, L 2 fc = 1.998); 43 upregulated genes were annotated in "ethylene-activated signaling pathway" (GO:0009873), such as fatty acid accumulation during seed maturation related transcription factor WRI1 (Cluster-6074.11856, L 2 fc = 10.875).…”

A SNP of HD-ZIP I transcription factor leads to distortion of trichome morphology in cucumber (Cucumis sativus L.)

“…Gibberellins promote trichome production in Arabidopsis through up-regulation of GL1 and TTG genes [57]. In cucumber, the application of GA showed a positive effect on fruit trichome initiation [45]. CsTTG1 acts in parallel to Mict/csgl1, a key trichome formation factor that regulates the initiation of fruit trichome and CsTTG1 can directly interact with Mict [58].…”

“…The development of glandular trichomes has multiple stages, including initiation and expansion of the trichome precursor cell protuberating out of the epidermal surface, followed by periclinal bipartition to two cells (top and bottom) which later form the head region and the stalk, respectively, through subsequent cell divisions [45]. Disruption of the Mict locus led to abnormal trichomes with a greatly reduced number of cells, aberrant cell shapes and organization, and branched trichomes (Fig.…”

“…Trend 2 is similar to the trend of trichome length and Trend 1 is opposite, which means these genes may function on the length of trichomes. Phytohormone treatments influence cucumber trichome development and morphogenesis [44][45][46]. STRING analysis [47] was used to predict the functional association networks of the homologs to Arabidopsis among these DEGs.…”

Study on Paraffin Section Technology of Fruit Tumor Tissues in Cucumber (<i>Cucumis sativus</i> L.)

“…Warty fruit is one of the highly valuable external quality traits (spine color, spine number, spine size, fruit colors, dull fruit skin, immature fruit color and ribbed fruit etc. ), which are closely related to the economic values of cucumber (Dijkuizen and Staub, 2002;Fazio et al, 2003;Di et al, 2018;Zhang et al, 2018;Xue et al, 2019). Compared with warty fruit varieties, smooth and non-warty fruit varieties have the advantages of less pollution, more convenience in cleaning and packing, higher resistance in transportation and storage etc., and its market price is high than that of the common cucumber (Wang et al, 2007).…”