Apoplastic modifications in plant reproductive development: The (w)hole story

Angiosperm reproductive structures (anthers and ovules/seeds) are complex assemblies containing highly specialized, metabolically diverse, and in some cases genetically distinct compartments. Their successful development depends both on strict inter-tissue coordination, and upon selectively gated inter-tissue communication, particularly at the metabolic level. For these two requirements to be met, dynamic, extensive, and precise remodelling of tissue interfaces, affecting both symplastic (direct cytoplasm-cytoplasm) and apoplastic (involving diffusion through the extracellular matrix) connectivity, is a prerequisite. I will concentrate on apoplastic modifications occurring between key compartments in the developing seeds and anthers of Arabidopsis thaliana. I aim to illustrate how related peptide-mediated inter-tissue dialogues are used in both systems to ensure the timely deposition of intact apoplastic filters (barriers). I will present recent unpublished work on the functional and compositional characterisation of a novel apoplastic filter (barrier) present within the maternal tissues of the developing anther.

References

A two-way molecular dialogue between embryo and endosperm is required for seed development. Doll NM, Royek S, Fujita S, Okuda S, Chamot S, Stintzi A, Widiez T, Hothorn M, Schaller A, Geldner N, Ingram G. Science. 2020 Jan 24;367(6476):431-435. doi: 10.1126/science.aaz4131. PMID: 31974252

A stress-response-related inter-compartmental signalling pathway regulates embryonic cuticle integrity in Arabidopsis. Creff A, Brocard L, Joubès J, Taconnat L, Doll NM, Marsollier AC, Pascal S, Galletti R, Boeuf S, Moussu S, Widiez T, Domergue F, Ingram G. PLoS Genet. 2019 Apr 18;15(4):e1007847. doi: 10.1371/journal.pgen.1007847.

A peptide-mediated, multilateral molecular dialogue for the coordination of pollen wall formation. Truskina J, Brück S, Stintzi A, Boeuf S, Doll NM, Fujita S, Geldner N, Schaller A, Ingram GC. Proc Natl Acad Sci U S A. 2022 May 31;119(22):e2201446119. doi: 10.1073/pnas.2201446119. Epub 2022 May 24. PMID: 35609199

The Endosperm-Derived Embryo Sheath Is an Anti-adhesive Structure that Facilitates Cotyledon Emergence during Germination in Arabidopsis. Doll NM, Bovio S, Gaiti A, Marsollier AC, Chamot S, Moussu S, Widiez T, Ingram G. Curr Biol. 2020 Mar 9;30(5):909-915.e4. doi: 10.1016/j.cub.2019.12.057. Epub 2020 Feb 20. PMID: 32155415