Auxin Response Dynamics During Wild-Type and entire Flower Development in Tomato

Abstract

The plant hormone auxin is a major regulator of plant development and response to environmental cues. Auxin plays a particularly central role in flower development, but the knowledge of its role of flower development in crop plants with fleshy fruits, such as tomato, is still scarce. Mutations in the Aux/IAA gene ENTIRE/Indole Acetic Acid 9 (E/IAA9) lead to the precocious development of young gynoecia into parthenocarpic fruits. Here, we compared the distribution of the auxin response sensor DR5::VENUS and the auxin efflux transporter PIN1 between the wild type and entire during successive stages of flower and fruit development. Up-regulation of the DR5::VENUS signal in the shoot apical meristem (SAM) was observed upon the transition to flowering, implicating a possible role for auxin in the transition from a vegetative SAM into an inflorescence meristem. DR5::VENUS was expressed in all initiating floral organs. Additionally, DR5::VENUS was highly expressed during gametogenesis, in both male and female organs, and in the developing seeds during embryogenesis. DR5::VENUS is expressed in functional cell layers such as the anther stomium and tapetum, suggesting that auxin plays a role in flower organ development and function. The entire mutation affected DR5::VENUS expression patterns during inflorescence formation and flower organ development, which correlated with phenotypic alterations. We also show dynamic distribution and localization of the auxin transporter PIN1 during flower and fruit organ development. These results emphasize the dynamic auxin response in inflorescence and flower development and suggest multiple roles of auxin in these processes.

Tuning of SlARF10A dosage by sly‐miR160a is critical for auxin‐mediated compound leaf and flower development

“…Auxin also regulates floral organ initiation, identity, and patterning (Reinhardt et al, 2000;Cheng et al, 2006;Kaufmann et al, 2009). Accordingly, in tomato flower, an auxin response signal has been observed in all the floral whorls during early bud development and later became prominent in the male and female reproductive organs (Goldental-Cohen et al, 2017). The abnormal floral organ patterning displayed by the CR-slmir160a mutants indicated that sly-miR160a is required also for these auxin-dependent processes.…”

Auxin Homeostasis in Arabidopsis Ovules Is Anther-Dependent at Maturation and Changes Dynamically upon Fertilization

“…A tight communication between different female reproductive tissues as well as between female and male reproductive organs is essential to allow successful fertilization and subsequent development and growth of embryos, seed and fruit. Although, auxin has been implicated in the coordination of these transition events in different species ( Dorcey et al, 2009 ; Fuentes and Vivian-Smith, 2009 ; Figueiredo et al, 2016 ; Goldental-Cohen et al, 2017 ), the spatiotemporal details, as well as the identity of the main framework for regulatory processes have largely remained elusive. Here we present a first map of auxin biosynthesis, transport, conjugation and sensing shortly before as well as after fertilization in the model plant Arabidopsis ( Figure 5 ).…”

Transcriptomes Analysis Reveals Novel Insight Into the Molecular Mechanisms of Somatic Embryogenesis in Hevea Brasiliensis

“…Dynamic change of endogenous IAA has been proved to induce plant SE and improved SE competency [58]. Auxin/Indole-3-Acetic Acids (Aux/IAAs), Gretchen Hagen3s (GH3s), small auxin upregulated RNAs (SAURs) and auxin response factor (ARF) have been identi ed as auxin-responsive genes in auxin signaling and homeostasis [59][60][61], can regulate downstream genes precisely and rapidly, and further regulated plant growth and developmental processes. Aux/IAA family play a key role in inhibiting the expression levels of genes transcriptional activated by ARFs [62,63].…”