High-Temperature-Induced Defects in Tomato (Solanum lycopersicum) Anther and Pollen Development Are Associated with Reduced Expression of B-Class Floral Patterning Genes

Citation: Muller, F., Xu, J. M., Kristensen, L., Wolters-Arts, M., de Groot, P. F. M., Jansma, S. Y., . . . Rieu, I. (2016). High-Temperature-Induced Defects in Tomato (Solanum lycopersicum) Anther and Pollen Development Are Associated with Reduced Expression of B-Class Floral Patterning Genes. Plos One, 11(12), 14. doi:10.1371/journal.pone.0167614Sexual reproduction is a critical process in the life-cycle of plants and very sensitive to environmental perturbations. To better understand the effect of high temperature on plant reproduction, we cultivated tomato (Solanum lycopersicum) plants in continuous mild heat. Under this condition we observed a simultaneous reduction in pollen viability and appearance of anthers with pistil-like structures, while in a more thermotolerant genotype, both traits were improved. Ectopic expression of two pistil-specific genes, TRANSMITTING TISSUE SPECIFIC and TOMATO AGAMOUS LIKE11, in the anthers confirmed that the anthers had gained partial pistil identity. Concomitantly, expression of the B-class genes TOMATO APETALA3, TOMATO MADS BOX GENE6 (TM6) and LePISTILLATA was reduced in anthers under continuous mild heat. Plants in which TM6 was partially silenced reacted hypersensitively to temperature elevation with regard to the frequency of pistilloid anthers, pollen viability and pollen quantity. Taken together, these results suggest that high-temperature induced down-regulation of tomato B-class genes contributes to anther deformations and reduced male fertility. Improving our understanding of how temperature perturbs the molecular mechanisms of anther and pollen development will be important in the view of maintaining agricultural output under current climate changes

Clinical Studies into the Causes of Idiopathic Macular Telangiectasia Type 2: Sleep Apnoea and Macular Telangiectasia: The SAMTel Project

Purpose: To assess the prevalence of Obstructive Sleep Apnoea (OSA) in a population with Macular Telangiectasia Type 2 (MacTel) and how OSA impacts on MacTel progression. Methods: In this case-control study participants completed a questionnaire which incorporated the Berlin Questionnaire (BQ) and questions regarding anthropometric data and medical history. A subset was sequentially selected to undertake overnight sleep analysis using the ResMed ApneaLink™. Using data acquired from the Busselton Population and Medical Research Foundation participants were case-matched based on age, sex and body mass index (BMI) along with, where possible, the presence of hypertension and diabetes. Results: There were 57 (30 ApneaLink) MacTel and 183 controls, respectively. There was no difference in self-reported sleep disordered breathing outcomes between the cohorts using the BQ (p=0.95). Analysis of key indices from ApneaLink recordings found that those with an Apnoea – Hypopnoea Index (AHI) and Oxygen Desaturation Index (ODI) > 5 episodes per hour had a more advanced stage of MacTel (AHI p = 0.05, ODI p = 0.03). 2 year MacTel disease progression rates were unremarkable. Conclusion: Patients with MacTel have a high prevalence of OSA which appears to result in a more advanced form of the disease

Semi-viviparous embryo development and dehydrin expression in the mangrove Rhizophora mucronata Lam.

Rhizophora mucronata Lam. is a tropical mangrove with semi-viviparous (cotyledon body protrusion before shedding), non-quiescent and non-desiccating (recalcitrant) seeds. As recalcitrance has been thought to relate to the absence of desiccation-related proteins such as dehydrins, we for the first time systematically described and classified embryogenesis in R. mucronata and assessed the presence of dehydrin-like proteins. Embryogenesis largely follows the classic pattern till stage eight, the torpedo stage, with the formation of a cotyledonary body. Ovule and embryo express radical adaptations to semi-vivipary in the saline environment: (1) A large, highly vacuolated and persistent endosperm without noticeable food reserves that envelopes the developing embryo. (2) Absence of vascular tissue connections between embryo and maternal tissue, but, instead, transfer layers in between endosperm and integument and endosperm and embryo. Dehydrin-like proteins (55–65 kDa) were detected by the Western analysis, in the ovules till stage 10 when the integuments are dehisced. An additional 50 kDa band was detected at stages 6–8. Together these results suggest a continuous flow of water with nutrients from the integument via the endosperm to the embryo, circumventing the vascular route and probably suppressing the initially induced dehydrin expression

Stigma development in Nicotiana tabacum : cell death in transgenic plants as a marker to follow cell fate at high resolution

Contains fulltext : 16826.pdf (publisher's version ) (Open Access

Ensuring Reproduction at High Temperatures: The Heat Stress Response during Anther and Pollen Development

Contains fulltext : 116975.pdf (publisher's version ) (Open Access

The role of lipids in pollen tube penetration

Item does not contain fulltextXVth International Congress on Sexual Plant Reproductio