Evolutionary ecophysiology of seed desiccation sensitivity

2018 ◽  
Vol 45 (11) ◽  
pp. 1083 ◽  
Author(s):  
Alexandre Marques ◽  
Gonda Buijs ◽  
Wilco Ligterink ◽  
Henk Hilhorst

Desiccation sensitive (DS) seeds do not survive dry storage due to their lack of desiccation tolerance. Almost half of the plant species in tropical rainforests produce DS seeds and therefore the desiccation sensitivity of these seeds represents a problem for and long-term biodiversity conservation. This phenomenon raises questions as to how, where and why DS (desiccation sensitive)-seeded species appeared during evolution. These species evolved probably independently from desiccation tolerant (DT) seeded ancestors. They adapted to environments where the conditions are conducive to immediate germination after shedding, e.g. constant and abundant rainy seasons. These very predictable conditions offered a relaxed selection for desiccation tolerance that eventually got lost in DS seeds. These species are highly dependent on their environment to survive and they are seriously threatened by deforestation and climate change. Understanding of the ecology, evolution and molecular mechanisms associated with seed desiccation tolerance can shed light on the resilience of DS-seeded species and guide conservation efforts. In this review, we survey the available literature for ecological and physiological aspects of DS-seeded species and combine it with recent knowledge obtained from DT model species. This enables us to generate hypotheses concerning the evolution of DS-seeded species and their associated genetic alterations.

2000 ◽  
Vol 10 (3) ◽  
pp. 393-396 ◽  
Author(s):  
Nathalie Chabrillange ◽  
Stéphane Dussert ◽  
Florent Engelmann ◽  
Sylvie Doulbeau ◽  
Serge Hamon

AbstractLarge differences in seed desiccation sensitivity have been observed previously among ten coffee species (Coffea arabica, C. brevipes, C. canephora, C. eugenioides, C. humilis, C. liberica, C. pocsii, C. pseudo-zanguebariae, C. sessiliflora and C.stenophylla). Of these species,C. libericaandC. humiliswere the most sensitive to desiccation andC. pseudozanguebariaethe most tolerant. A study was carried out using the same seed lots to investigate if these differences in desiccation tolerance could be correlated with differences in soluble sugar content. Soluble sugars were extracted from dry seeds and analysed using high performance liquid chromatography. The seed monosaccharide (glucose and fructose) content was very low (1.5 to 2 mg g-1dry weight [dw]) in all species studied. The sucrose content ranged from 33 mg g-1dw inC. libericaseeds to 89 mg g-1dw in seeds ofC. pocsii. Raffinose was detected in the seeds of only five species (C.arabica, C.brevipes, C.humilis, C.sessiliflora, C.stenophylla), among which only three species (C.arabica, C.sessilifloraandC.brevipes) also contained stachyose. Both raffinose and stachyose were present in very low quantities (0.3–1.4 mg g-1dw and 0.1–0.7 mg g-1dw, respectively). Verbascose was never detected. No significant relationship was found between seed desiccation sensitivity and: (i) the sugar content; (ii) the presence/absence of oligosaccharides; and (iii) the oligosaccharide:sucrose ratio.


Proteomes ◽  
2017 ◽  
Vol 5 (4) ◽  
pp. 19 ◽  
Author(s):  
Matthieu Villegente ◽  
Philippe Marmey ◽  
Claudette Job ◽  
Marc Galland ◽  
Gwendal Cueff ◽  
...  

2016 ◽  
Vol 38 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Maria Cecília Dias Costa ◽  
José Marcio Rocha Faria ◽  
Anderson Cleiton José ◽  
Wilco Ligterink ◽  
Henk W.M. Hilhorst

Abstract: Seed desiccation tolerance (DT) and longevity are necessary for better dissemination of plant species and establishment of soil seed bank. They are acquired by orthodox seeds during the maturation phase of development and lost upon germination. DT can be re-induced in germinated seeds by an osmotic and/or abscisic acid treatment. However, there is no information on how these treatments affect seed longevity. Germinated Sesbania virgata seeds were used as a model system to investigate the effects of an osmotic treatment to re-establish DT on seed longevity. Longevity of germinated S. virgata seeds treated and non-treated by an osmoticum was analysed after storage or artificial ageing. The radicle is the most sensitive organ, the cotyledons are the most resistant, and the ability to produce lateral roots is the key for whole seed survival. Germinated S. virgata seeds with 1mm protruded radicle tolerate desiccation and storage for up to three months without significant losses in viability. An osmotic treatment can improve DT in these seeds, but not longevity. Germinated S. virgata seeds are a good model to study DT uncoupled from longevity. Further studies are necessary to unveil the molecular mechanisms involved in both DT and longevity.


2021 ◽  
pp. 1-7
Author(s):  
Yasoja S. Athugala ◽  
K. M. G. Gehan Jayasuriya ◽  
A. M. T. A. Gunaratne ◽  
Carol C. Baskin

Abstract Although the level of seed desiccation sensitivity (LSDS) may have an impact on plant species conservation, information is available for <10% of tropical angiosperms. A study was conducted to assess the LSDS of 28 tropical montane species in Sri Lanka. Seeds were extracted from freshly collected fruits. Initial weight was recorded, and thousand seed weight (TSW) was calculated. Seed moisture content (MC) was determined. LSDS was determined using seed desiccation experiments and predicted using the TSW–MC criterion. Seed storage behaviour was predicted using LSDS and storage data and using a model based on phylogenetic affiliation. The relationship between LSDS and seed dormancy, life form and forest strata was evaluated. Fresh seeds of only 12 species germinated to >80%. Although seeds of the other species had >80% viability, only 0–70% germinated due to dormancy. Seeds of five species had MC <15%, indicating desiccation tolerance (DT). Seeds of 12 species lost viability after desiccation, indicating desiccation sensitivity (DS). Seeds of Ardisia missionis, Psychotria gartneri and Psychotria nigra remained viable after desiccation, showing DT. Seeds of 17 species were DS and those of 11 species DT. The TSW of four species was >500 g. Thus, seeds of other species were predicted to be DT by the TSW–MC criterion. A relationship was identified between LSDS and the forest strata of the species. More canopy species produced DS than DT seeds. Since seeds of most of the studied species were DS, these species may be threatened due to prolonged droughts predicted for the region due to climate change.


2021 ◽  
Vol 8 ◽  
Author(s):  
Claudia Richter ◽  
Rabea Hinkel

Diabetes and the often accompanying cardiovascular diseases including cardiomyopathy represent a complex disease, that is reluctant to reveal the molecular mechanisms and underlying cellular responses. Current research projects on diabetic cardiomyopathy are predominantly based on animal models, in which there are not only obvious advantages, such as genetics that can be traced over generations and the directly measurable influence of dietary types, but also not despisable disadvantages. Thus, many studies are built up on transgenic rodent models, which are partly comparable to symptoms in humans due to their genetic alterations, but on the other hand are also under discussion regarding their clinical relevance in the translation of biomedical therapeutic approaches. Furthermore, a focus on transgenic rodent models ignores spontaneously occurring diabetes in larger mammals (such as dogs or pigs), which represent with their anatomical similarity to humans regarding their cardiovascular situation appealing models for testing translational approaches. With this in mind, we aim to shed light on the currently most popular animal models for diabetic cardiomyopathy and, by weighing the advantages and disadvantages, provide decision support for future animal experimental work in the field, hence advancing the biomedical translation of promising approaches into clinical application.


2021 ◽  
Vol 22 (3) ◽  
pp. 1201
Author(s):  
Hsuan Peng ◽  
Kazuhiro Shindo ◽  
Renée R. Donahue ◽  
Ahmed Abdel-Latif

Stem cell-based cardiac therapies have been extensively studied in recent years. However, the efficacy of cell delivery, engraftment, and differentiation post-transplant remain continuous challenges and represent opportunities to further refine our current strategies. Despite limited long-term cardiac retention, stem cell treatment leads to sustained cardiac benefit following myocardial infarction (MI). This review summarizes the current knowledge on stem cell based cardiac immunomodulation by highlighting the cellular and molecular mechanisms of different immune responses to mesenchymal stem cells (MSCs) and their secretory factors. This review also addresses the clinical evidence in the field.


2021 ◽  
pp. 002224372110092
Author(s):  
Zhenling Jiang ◽  
Dennis J. Zhang ◽  
Tat Chan

This paper studies how receiving a bonus changes the consumers’ demand for auto loans and the risk of future delinquency. Unlike traditional consumer products, auto loans have a long-term impact on consumers’ financial state because of the monthly payment obligation. Using a large consumer panel data set of credit and employment information, the authors find that receiving a bonus increases auto loan demand by 21 percent. These loans, however, are associated with higher risk, as the delinquency rate increases by 18.5 −31.4 percent depending on different measures. In contrast, an increase in consumers’ base salary will increase the demand for auto loans but not the delinquency. By comparing consumers with bonuses with those without bonuses, the authors find that bonus payments lead to both demand expansion and demand shifting on auto loans. The empirical findings help shed light on how consumers make financial decisions and have important implications for financial institutions on when demand for auto loans and the associated risk arise.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 656
Author(s):  
Jing Jin ◽  
Rui Shi ◽  
Ramsey Steven Lewis ◽  
Howard David Shew

Phytophthora nicotianae is a devastating oomycete plant pathogen with a wide host range. On tobacco, it causes black shank, a disease that can result in severe economic losses. Deployment of host resistance is one of the most effective means of controlling tobacco black shank, but adaptation to complete and partial resistance by P. nicotianae can limit the long-term effectiveness of the resistance. The molecular basis of adaptation to partial resistance is largely unknown. RNAseq was performed on two isolates of P. nicotianae (adapted to either the susceptible tobacco genotype Hicks or the partially resistant genotype K 326 Wz/Wz) to identify differentially expressed genes (DEGs) during their pathogenic interactions with K 326 Wz/Wz and Hicks. Approximately 69% of the up-regulated DEGs were associated with pathogenicity in the K 326 Wz/Wz-adapted isolate when sampled following infection of its adapted host K 326 Wz/Wz. Thirty-one percent of the up-regulated DEGs were associated with pathogenicity in the Hicks-adapted isolate on K 326 Wz/Wz. A broad spectrum of over-represented gene ontology (GO) terms were assigned to down-regulated genes in the Hicks-adapted isolate. In the host, a series of GO terms involved in nuclear biosynthesis processes were assigned to the down-regulated genes in K 326 Wz/Wz inoculated with K 326 Wz/Wz-adapted isolate. This study enhances our understanding of the molecular mechanisms of P. nicotianae adaptation to partial resistance in tobacco by elucidating how the pathogen recruits pathogenicity-associated genes that impact host biological activities.


2021 ◽  
Vol 22 (10) ◽  
pp. 5145
Author(s):  
Giuseppe Schepisi ◽  
Caterina Gianni ◽  
Sara Bleve ◽  
Silvia De Padova ◽  
Cecilia Menna ◽  
...  

Testicular cancer (TC) is the most frequent tumor in young males. In the vast majority of cases, it is a curable disease; therefore, very often patients experience a long survival, also due to their young age at diagnosis. In the last decades, the role of the vitamin D deficiency related to orchiectomy has become an increasingly debated topic. Indeed, vitamin D is essential in bone metabolism and many other metabolic pathways, so its deficiency could lead to various metabolic disorders especially in long-term TC survivors. In our article, we report data from studies that evaluated the incidence of hypovitaminosis D in TC survivors compared with cohorts of healthy peers and we discuss molecular mechanisms and clinical implications.


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