RESUMEN
Pollen fertility is critical for successful fertilization and, accordingly, for crop yield. While sugar unloading affects the growth and development of all types of sink organs, the molecular nature of sugar import to tomato (Solanum lycopersicum) pollen is poorly understood. However, sugar will eventually be exported transporters (SWEETs) have been proposed to be involved in pollen development. Here, reverse transcription-quantitative polymerase chain reaction (PCR) revealed that SlSWEET5b was markedly expressed in flowers when compared to the remaining tomato SlSWEETs, particularly in the stamens of maturing flower buds undergoing mitosis. Distinct accumulation of SlSWEET5b-ß-glucuronidase activities was present in mature flower buds, especially in anther vascular and inner cells, symplasmic isolated microspores (pollen grains), and styles. The demonstration that SlSWEET5b-GFP fusion proteins are located in the plasma membrane supports the idea that the SlSWEET5b carrier functions in apoplasmic sugar translocation during pollen maturation. This is consistent with data from yeast complementation experiments and radiotracer uptake, showing that SlSWEET5b operates as a low-affinity hexose-specific passive facilitator, with a Km of â¼36 mM. Most importantly, RNAi-mediated suppression of SlSWEET5b expression resulted in shrunken nucleus-less pollen cells, impaired germination, and low seed yield. Moreover, stamens from SlSWEET5b-silenced tomato mutants showed significantly lower amounts of sucrose (Suc) and increased invertase activity, indicating reduced carbon supply and perturbed Suc homeostasis in these tissues. Taken together, our findings reveal the essential role of SlSWEET5b in mediating apoplasmic hexose import into phloem unloading cells and into developing pollen cells to support pollen mitosis and maturation in tomato flowers.
Asunto(s)
Solanum lycopersicum , Flores/genética , Flores/metabolismo , Hexosas/metabolismo , Solanum lycopersicum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen , Sacarosa/metabolismoRESUMEN
Through reviewing the current international market for traditional Chinese medicine (TCM), this paper identified the internationalization challenges for TCM, including unclear therapeutic material basis and mechanism, difficulty of quality control, low preparation level, registration/policy barriers, and shortage of intellectual property. To deal with these challenges, suggestions were given including: (1) product innovation of TCM (study the TCM by using the methods and means of western medicine; innovate the basic theory of TCM; develop TCM health product); (2) standard innovation of TCM; (3) building big data platform of Chinese medicine (big data platform of TCM preparation; big data platform on the quality of TCM).
RESUMEN
BACKGROUND: Smoking cessation counselling is a key component of medical treatment and health promotion activities performed by general practitioners (GPs); however, GPs are often left wondering why their patients continue to smoke in spite of being given information about the damaging health effects and medical treatments. The concept of resilience to smoking is an emerging idea that offers an innovative perspective to smoking cessation. AIMS: To understand why some people continue to smoke in spite of well-known adverse health effects, what and how resilience factors impact on people's smoking, and the role and limitations of the GP in fostering resilience to smoking. METHOD: A qualitative study of 22 oral-history interviews was conducted in Adelaide, South Australia. Interviews were audio-recorded, transcribed and analysed for emergent themes. RESULTS: The main themes of most relevance to GPs are the resilience to health messages, resilience factors associated with smoking abstinence and the common pathways that lead to successful smoking cessation. DISCUSSION: Understanding smoking and resilience can assist the GP to provide more effective and supportive smoking cessation assistance. The GP may assist in the process by fostering the adoption of resilience factors, much of which is already part of routine GP work but may not yet be considered part of a holistic smoking cessation strategy. Through this holistic approach, smoking cessation is likely to be just one of many physical and social benefits, and avoids victim blaming. Broad system change to increase the levels of resilience within individuals and communities may then mean that smokers can stop more easily with brief interventions. Such changes are beyond the limits of a single GP, but provide opportunities to lobby government for future public health programmes aimed at promoting both the internal traits and external resources that are required for resilience building.