Integration of Hormonal and Nutritional Cues Orchestrates Progressive Corolla Opening  

Abstract

Flower opening is essential for pollination and thus successful sexual reproduction; however, the underlying mechanisms of its timing control remain largely elusive. We identify a unique cucumber (Cucumis sativus) line '6457' that produces normal ovaries when nutrients are under-supplied, and super ovaries (87%) with delayed corolla opening when nutrients are oversupplied. Corolla opening in both normal and super ovaries is divided into four distinct phases, namely the green bud, green-yellow bud, yellow bud, and flowering stages, along with progressive color transition, cytological tuning, and differential expression of 14,282 genes. In the super ovary, cell division and cell expansion persisted for a significantly longer period of time; the expressions of genes related to photosynthesis, protein degradation, and signaling kinases were dramatically upregulated, whereas the activities of most transcription factors and stress-related genes were significantly down-regulated; concentrations of cytokinins (CKs) and gibberellins were higher in accordance with reduced cytokinin conjugation and degradation and increased expression of gibberellin biosynthesis genes. Exogenous CK application was sufficient for the genesis of super ovaries, suggesting a decisive role of CKs in controlling the timing of corolla opening. Furthermore, 194 out of 11,127 differentially expressed genes identified in pairwise comparisons, including critical developmental, signaling, and cytological regulators, contained all three types of cis-elements for CK, nitrate, and phosphorus responses in their promoter regions, indicating that the integration of hormone modulation and nutritional regulation orchestrated the precise control of corolla opening in cucumber. Our findings provide a valuable framework for dissecting the regulatory pathways for flower opening in plants.The flower is the most distinguishing organ in higher plants, and artists and scientists have been attracted to explore the mystery of flower structure and origin for decades. The evolution of flowering plants was greatly accelerated approximately 100 million years ago with the development of flowers, which were essential for recruiting animals to help distribute pollen and seeds (Danielson and Frommer, 2013). Flowers are produced from a specialized structure in the shoot tip called the shoot apical meristem, which consists of a pool of stem cells that continuously divide and replenish themselves (Fletcher et al., 1999). Morphologically, flowers are comprised of four basic structures arranged in concentric whorls: sepals in the outermost whorl 1, petals in whorl 2, stamens in whorl 3, and carpels in the innermost whorl 4. Bisexual flowers possess all four basic structures, while unisexual flowers lack one or more structures, usually the male organ stamen or the female organ carpel (Dellaporta and Calderon-Urrea, 1993). In flowering plants, approximately 90% species produce bisexual flowers, 6% species are dioecious with male and female flowers on separate plants, and 4% species a...

CsBRC1 inhibits axillary bud outgrowth by directly repressing the auxin efflux carrier CsPIN3 in cucumber

“…Illumina HiSeq 2000 platform was used to generate 100-bp paired-end reads. Bioinformatic analyses of RNA-Seq data were performed as previously described (56).…”

MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativa L.)

“…For examples, in cucumber, time course transcriptome analyses of corolla indicated that cytokinin and nutrition played essential roles for the delayed flower opening in super ovary (Sun et al, 2016). Transcriptional sequencing has also been used to clarify the gene expression patterns during floral development in bamboo ( Dendrocalamus latiflorus ) (Zhang et al, 2012), to identify the genes associated with flowering time in Oncidium (Chang et al, 2011), and to explore the floral odor related genes in Phalaenopsis (Hsiao et al, 2006).…”

Efecto de las giberelinas en el rendimiento de chile jalapeño (Capsicum annuum L.)

“…Los resultados anteriores muestran que con una dosis baja de GA3 y una fertilización con nitrato de potasio y nitrato de calcio se obtienen rendimientos superiores que utilizando la solución nutritiva en la producción de chile jalapeño en invernadero. Lo anterior, podría ofrecer una ventaja a los productores en el ahorro de insumos agrícolas, ya que se abaratarían los costos de producción para obtener una buena producción en el cultivo de chile (Sun et al, 2016).…”

“…Es empleado como condimento, suplemento culinario, medicina, en cosméticos y planta ornamental (Ravishankar et al, 2003;Hasan et al, 2015). Además, el fruto de Capsicum tiene alto contenido de vitamina C, carotenoides y flavonoides (Kumar y Tata, 2009;Sun et al, 2016). Globalmente, China es el más grande productor de chile, seguido por México (FAO, 2014).…”