De Micco V, De Pascale S, Paradiso R, Aronne G
Department of Agriculture, University of Naples Federico II, Portici, Naples, Italy.
Plant Biol (Stuttg). 2014 Jan;16 Suppl 1:31-8. doi: 10.1111/plb.12098. Epub 2013 Sep 9.
Human inhabitation of Space requires the efficient realisation of crop cultivation in bioregenerative life-support systems (BLSS). It is well known that plants can grow under Space conditions; however, perturbations of many biological phenomena have been highlighted due to the effect of altered gravity and its possible interactions with other factors. The mechanisms priming plant responses to Space factors, as well as the consequences of such alterations on crop productivity, have not been completely elucidated. These perturbations can occur at different stages of plant life and are potentially responsible for failure of the completion of the seed-to-seed cycle. After brief consideration of the main constraints found in the most recent experiments aiming to produce seeds in Space, we focus on two developmental phases in which the plant life cycle can be interrupted more easily than in others also on Earth. The first regards seedling development and establishment; we discuss reasons for slow development at the seedling stage that often occurs under microgravity conditions and can reduce successful establishment. The second stage comprises gametogenesis and pollination; we focus on male gamete formation, also identifying potential constraints to subsequent fertilisation. We finally highlight how similar alterations at cytological level can not only be common to different processes occurring at different life stages, but can be primed by different stress factors; such alterations can be interpreted within the model of 'stress-induced morphogenic response' (SIMR). We conclude by suggesting that a systematic analysis of all growth and reproductive phases during the plant life cycle is needed to optimise resource use in plant-based BLSS.
人类对太空的居住需要在生物再生生命支持系统（BLSS）中高效实现作物种植。众所周知，植物可以在太空条件下生长；然而，由于重力改变的影响及其与其他因素可能的相互作用，许多生物现象受到了干扰。引发植物对太空因素反应的机制，以及这种改变对作物生产力的影响，尚未完全阐明。这些干扰可能发生在植物生命的不同阶段，并可能导致种子到种子周期无法完成。在简要考虑了最近旨在在太空中生产种子的实验中发现的主要限制因素后，我们关注植物生命周期中两个比地球上其他阶段更容易中断的发育阶段。第一个阶段是幼苗发育和定植；我们讨论了在微重力条件下经常出现的幼苗阶段发育缓慢的原因，这可能会降低成功定植的几率。第二个阶段包括配子发生和授粉；我们关注雄配子的形成，也确定了对后续受精的潜在限制。我们最后强调，细胞学水平上的类似改变不仅在不同生命阶段发生的不同过程中很常见，而且可以由不同的应激因素引发；这种改变可以在“应激诱导形态发生反应”（SIMR）模型中得到解释。我们建议，需要对植物生命周期中的所有生长和生殖阶段进行系统分析，以优化基于植物的BLSS中的资源利用。
