ITRABAE · Investigating the transcriptional regulation of auxin biosynthesis in Arabidopsis embryo
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-01-01 → 2022-12-31
- EU contribution
- €144,981
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Investigating the transcriptional regulation of auxin biosynthesis in Arabidopsis embryo
Seeds have considerable biological and commercial importance. They are a major source of food and nutrition for most of the world’s population. In plants, seeds protect and nourish the developing embryo, thus ensuring reproductive success. Therefore, improvement of seed quality and quantity is a key issue. Moreover, this challenge is compounded by climate changes, with an increase in average temperatures over the past decades already negatively impacting seed production. Seed development proceeds through two stages, (i) morphogenesis and (ii) maturation. During embryogenesis, a single-cell zygote divides into a multicellular embryo. The mature embryo encloses all the features of a new plantlet that will develop after germination. Among various hormones, phytohormone auxin plays an essential role in embryo development. Auxin defines embryo patterning through its concentration gradients, maintained by auxin biosynthesis combined with transport. However, how local embryonic auxin biosynthesis is transcriptionally regulated is not known. In this project, we aimed to elucidate the transcriptional regulation of auxin biosynthetic genes during embryo development with an overall goal of improving seed development using auxin as a tool. The Objectives of this project were 1) to elucidate the transcriptional regulation of auxin biosynthetic genes (TAA1 and YUCs) by the identified AGL transcription factors (TFs) during embryo development and 2) to characterise the impact of high temperatures on this regulation. In conclusion, we identified the AGL5 transcription factor as a novel regulator of auxin biosynthesis. It interacted the promoters of auxin biosynthetic genes (TAA1, YUC8, and YUC9) and activated their transcription. Over-expression of AGL5 could up-regulate the expression of auxin biosynthetic genes. It acted redundantly with SHP1 and STK to control ovule and seed development. Overall, this work will pave the way for understanding a key mechanism for auxin production to mediate proper ovule and seed development, a finding widely relevant to flowering plants.
Data: CORDIS, © European Union
Project objective
Survival of flowering plants is determined by the proper production of seed, whose shape and size are defined by the development of an embryo. Such mature embryo mimics the body pattern of the new plant that will develop after germination. Auxin is a key regulator of various aspects of plant development, including embryo morphogenesis. Cellular auxin gradients, maintained by auxin production along with signalling and transport, are essential for proper embryo development. The embryonic local auxin biosynthesis appears spatiotemporally controlled, necessitating the presence of regulatory networks. Also, it became evident that auxin plays a critical role as an integrator of environmental cues, notably high temperatures, known to impair seed production. Thus, I aim at deciphering the molecular and genetic mechanisms behind the spatiotemporal regulation of auxin biosynthetic genes during embryo development, and how this regulatory network is impacted by heat stress. In the proposed work, I will functionally dissect the contribution of AGL transcription factors, identified in a yeast one-hybrid screen as binding to auxin biosynthetic promoters, to the direct regulation of auxin biosynthetic pathways using multidisciplinary approaches such as genetics, metabolomics, and molecular biology. Further, I will investigate whether high temperatures impact this regulation, notably at epigenetic levels. Overall, the proposed work would serve as an excellent foundation to dissect the mechanisms responsible for local auxin biosynthesis during embryo development, which would pave the way to devise strategies for mitigating the effects of climate warming on seed and plant morphogenesis.
Original text from CORDIS.
Participants
- Masarykova univerzita · BrnoCoordinatorCzechia
Links
Data: CORDIS, © European Union