When considering the issues associated with satisfying the legitimate needs of an increasing global population, Sir John Beddington, who is the UK Government Chief Scientific Adviser, has described the challenge of meeting the predicted increase in demands for energy (50% increase by 2030), food (50% increase by 2030) and fresh water (30% increase by 2030) whilst mitigating and adapting to climate change as constituting ‘the perfect storm’ (http://www.bis.gov.uk/assets/goscience/docs/p/perfect-storm-paper.pdf). In combating ‘the perfect storm’, plant research scientists have much to contribute. Globally, plant scientists are working in all the key areas: bioenergy, climate change mitigation/adaptation and the production of new, more resource use efficient varieties of crops.
New Phytologist is a journal that aims to publish the results of top-quality fundamental research and leaves more applied areas such as biotechnology to more specialized journals. However, as recognized by researchers in both the public and private sectors, it is the results of these fundamental investigations that often provide the insights that will be exploited in the more applied areas of our science. In this vein, inspection of recent issues of New Phytologist reveals that we have published several papers reporting insights into fundamental plant processes that could provide the insights required to solve ‘perfect storm’ problems.
Let's consider the challenge of feeding a significantly increased world population in the face of a 30% increase in demand for fresh water. This is likely to mean developing crops that use water more efficiently and/or are able to grow in environments where water is not plentiful. Whatever strategy underpins the breeding programme, it ultimately relies on insights from fundamental research. The remarkable thing is that, when it comes to dealing with reduced water availability, plants have evolved multiple strategies and we are continuing to discover more about the biology underpinning these adaptations. It has been known for a considerable time that certain species adopt ‘escape’ strategies where they complete their life cycle outwith the drought period, whereas others seek to ‘tolerate’ the period(s) of reduced water availability (see Franks, 2011 for full discussion of this topic).
To underline the fact that we are continuing to uncover new and unexpected insights into the ways that plants efficiently exploit water when it is in short supply, we need to consider the paper by Salguero-Gómez & Casper (2011). These workers were investigating the way in which some desert species are able to rapidly exploit the opportunities presented by pulse precipitation. They found that when the aridland species Cryptantha flava was exposed to a pulse of simulated rainfall it very rapidly produced fine roots that were initiated from a previously undescribed root type that they call the ‘short root’. The production of these new fine roots allows the plant to rapidly exploit the opportunity provided by the pulse of rainfall. Interestingly, the authors found that the fine roots were initiated at a scale smaller than the whole root system, suggesting that this species has evolved mechanisms capable of detecting and responding to highly localized sources of water. Before we leave roots, for those who want to learn more about root development, I want to highlight a very nice highly relevant review by Ive De Smet (2012) on lateral root initiation.
For the second example that reports insights into how plants control water usage and that might be exploited to tackle the ‘perfect storm’, we need to travel to the opposite end of the plant and focus on a paper based on modelling and the analysis of meta-data sets. New Phytologist has a long tradition of publishing the results of modelling studies and the paper by Vico et al. (2011) continues this distinguished tradition. Vico et al. (2011) were interested in understanding the strategies that plants use to efficiently exploit available light in understory environments, or more specifically how stomata balance the potentially conflicting demands to open and permit carbon dioxide uptake while concomitantly restricting water loss. To investigate this they first carried out a meta-analysis of the time taken to open in the light (τop) and close in the dark (τcl). This revealed that (1) τop tended to be faster than τcl in the majority of species examined, (2) graminoid stomata were the fastest responders while gymnosperms were the slowest, and (3) plants inhabiting dry habitats responded faster than wetland species. They also found something else interesting. When they plotted the experimental meta-data as τop against τcl they found, subject to the trends already noted, that the data clustered towards the centre of the ‘time of response space’. Or expressed another way, they never encountered species that opened their stomata very rapidly in the light and closed them very slowly in the dark (or the reverse). To test whether τop and τcl are ‘set’ to optimize light capture for photosynthesis whilst limiting transpiration and carbon costs for stomatal movement, the authors constructed a gas exchange model incorporating elements to take account of the bioenergetic costs of movement. Although the model needs further refinement, especially in terms of the energetic costs of movement, it revealed that opening and closure times tend to be consistent with the maximization of photosynthetic carbon gain whilst minimizing water loss and the energetic costs of stomatal opening.
For me, one of the most interesting things to come out of this study was the fact that the landscape of the ‘time of response space’ (referred to as the ‘delay space’ by the authors) was not fully populated. Given that we are making considerable strides in understanding the control of stomatal aperture (reviewed in Lawson, 2009) that will likely play out in being able to manipulate stomatal aperture, might we be able to exploit the unpopulated regions of the ‘time of response space’ to breed plants that are tailored to use the water available in a particular environment more efficiently?
Not that long ago, the introduction of a new trait such as the ‘short root’ into crop species or the manipulation of water usage through modifying stomatal development (Hunt et al., 2010) or function (see meeting report by Roelfsema & Kollist on the 29th New Phytologist Symposium; this issue, pp. 11–15) would have looked fanciful. However, evidence that we are entering an age where we are equipped to tackle such grand challenges can be found in the recent announcement that the Bill and Melinda Gates Foundation have awarded $9.8M to a consortium headed by Giles Oldroyd (John Innes Centre, UK) tasked with introducing nitrogen fixation into nonlegume crops (http://news.jic.ac.uk/2012/07/cereals-self-fertilise/). When it comes to tackling the challenges of the ‘perfect storm’, the ball is firmly in the court of plant scientists. I am confident that the community will rise to meet this important societal challenge and New Phytologist will certainly continue to publish the results of such investigations. Indeed, this first issue of the New Year reports on many interesting studies including those dealing with water stress (see Xu et al., pp. 139–150 and Zhang et al., pp. 314–322) and stomatal development (Laanemets et al., pp. 88–98). I hope you enjoy this first issue of 2013 and may I take this opportunity to thank our authors, reviewers and readers for their continued support in making New Phytologist the journal it is today.