Dimorphic fruits, seeds and seedlings as adaptation mechanisms to abiotic stress in unpredictable environments
Final Report Abstract
The aim of the SeedAdapt consortium project was to elucidate the molecular mechanisms of fruit/seed-related traits that evolved in annual plant species as adaptations to cope with abiotic stresses in harsh environments and upon climate change. The network SeedAdapt, a collaboration between six European partners with diverse and complementary expertise, investigated this interesting phenomenon by studying Aethionema arabicum, a small plant originating from the Mediterranean region and the Middle East. The species belongs to the family of crucifers (Brassicaceae or cabbage family) and is therefore also related to Arabidopsis, the famous model plant for genetic and molecular research. The network revealed that, in contrast to Arabidopsis which is a model for monomorphic plants, the SeedAdapt species Ae. arabicum is a dimorphic plant. It forms two morphologically distinct types of fruits and seeds on the same plant. It is proposed that this is a "don't put all eggs in one basket" risk management strategy to survive unpredictable environmental conditions and variable weather. The seed and fruit types differ with respect to several anatomical, biomechanical, physiological, and molecular features. The total number of fruits and the ratio between the two types depend on the developmental scheme of the flower branches, and change in response to different environmental conditions experienced during flowering. In a large experiment, we mimicked different environmental stress conditions by applying different temperatures during flowering. This resulted in altered fruit and seed numbers and different ratios between the two types. Interestingly, not only the numbers and ratios were altered, but also the intrinsic properties of the produced fruits and seeds. We further found for one of the dimorphic seed types that the fruit coats encasing the seeds confer dormancy and block the germination. Our work into the underpinning molecular mechanisms demonstrated that the interaction between environment and fruit/seed type affected the hormone contents, epigenetic regulation and gene expression patterns (transcriptomes). The availability of the Ae. arabicum genome facilitated our comparative investigation of abiotic stressrelated epigenomes, hormonomes, and transcriptomes, thereby making it an exciting time to study the remarkable plant diversity by moving beyond Arabidopsis and all other monomorphic plants. The large molecular datasets generated and all findings from this research are being published OpenAccess to make them widely available. The SeedAdapt consortium work has advanced our knowledge about plant-climate interactions and demonstrated that Ae. arabicum provides an excellent model system for studying the role of seed/fruit bet-hedging to survive unpredictable environments.
Publications
- (2016) Developmental control and plasticity of fruit and seed dimorphism in Aethionema arabicum. Plant Physiology 172 (3): 1691–1707
Lenser T, Graeber K, Cevik ÖS, Adigüzel N, Dönmez AA, Grosche C, Kettermann M, Mayland-Quellhorst S, Mérai Z, Mohammadin S, Nguyen T-P, Rümpler F, Schulze C, Sperber K, Steinbrecher T, Wiegand N, Strnad M, Mittelsten Scheid O, Rensing SA, Schranz ME, Theißen G, Mummenhoff K, Leubner-Metzger G
(See online at https://doi.org/10.1104/pp.16.00838) - (2017) Anatolian origins and diversification of Aethionema, the sister lineage of the core Brassicaceae. American Journal of Botany 104 (7): 1042–1054
Mohammadin S, Peterse K, van de Kerke SJ, Chatrou LW, Dönmez AA, Mummenhoff K, Pires JC, Edger PP, Al-Shehbaz IA, Schranz ME
(See online at https://doi.org/10.3732/ajb.1700091) - (2017) Comprehensive genome-wide classification reveals that many plant-specific transcription factors evolved in streptophyte algae. Genome Biology and Evolution 9 (12): 3384–3397
Wilhelmsson PKI, Mühlich C, Ullrich KK, Rensing SA
(See online at https://doi.org/10.1093/gbe/evx258) - (2017) Flowering Locus C (FLC) is a potential major regulator of glucosinolate content across developmental stages of Aethionema arabicum (Brassicaceae). Frontiers in Plant Science 8: 876
Mohammadin S, Nguyen T-P, van Weij MS, Reichelt M, Schranz ME
(See online at https://doi.org/10.3389/fpls.2017.00876) - (2018) Dispersal biophysics and adaptive significance of dimorphic diaspores in the annual Aethionema arabicum (Brassicaceae). New Phytologist
Arshad W, Sperber K, Steinbrecher T, Nichols B, Jansen VAA, Leubner-Metzger G, Mummenhoff K
(See online at https://doi.org/10.1111/nph.15490) - (2018) Genome-wide nucleotide diversity and associations with geography, ploidy level and glucosinolate profiles in Aethionema arabicum (Brassicaceae). Plant Systematics and Evolution 304 (5): 619–630
Mohammadin S, Wang W, Liu T, Moazzeni H, Ertugrul K, Uysal T, Christodoulou CS, Edger PP, Pires JC, Wright SI, Schranz ME
(See online at https://doi.org/10.1007/s00606-018-1494-3) - (2018) When the BRANCHED network bears fruit: How carpic dominance causes fruit dimorphism in Aethionema. The Plant Journal 94: 352–371
Lenser T, Tarkowská D, Novák O, Wilhelmsson PKI, Bennett T, Rensing SA, Strnad M, Theißen G
(See online at https://doi.org/10.1111/tpj.13861) - (2018). Two-tier morpho-chemical defense tactic in Aethionema via fruit morph plasticity and glucosinolates allocation in diaspores. Plant, Cell & Environment
Bhattacharya S, Mayland-Quellhorst S, Müller C, Mummenhoff K
(See online at https://doi.org/10.1111/pce.13462)
