scholarly journals The circadian clock contributes to the long-term water use efficiency of Arabidopsis

2019 ◽  
Author(s):  
Noriane M. L. Simon ◽  
Calum A. Graham ◽  
Nicholas E. Comben ◽  
Alistair M. Hetherington ◽  
Antony N. Dodd

AbstractIn plants, water use efficiency is a complex trait derived from numerous physiological and developmental characteristics. Here, we investigated the involvement of circadian regulation in long-term water use efficiency. Circadian rhythms are generated by the circadian oscillator, which provides a cellular measure of the time of day. In plants, the circadian oscillator contributes to the regulation of many aspects of physiology, including stomatal opening, the rate of photosynthesis, carbohydrate metabolism and developmental processes. We investigated in Arabidopsis the impact of the misregulation of genes encoding a large number of components of the circadian oscillator upon whole plant, long-term water use efficiency. From this, we identified a role for the circadian oscillator in water use efficiency. This appears to be due to contributions of the circadian clock to the control of transpiration and biomass accumulation. We also identified that the circadian oscillator within guard cells can contribute to long-term water use efficiency. Our experiments indicate that knowledge of circadian regulation will be important for developing future crops that use water more efficiently.One-sentence summaryThe circadian clock in Arabidopsis makes an important contribution to long-term water use efficiency.

2020 ◽  
Vol 183 (1) ◽  
pp. 317-330 ◽  
Author(s):  
Noriane M. L. Simon ◽  
Calum A. Graham ◽  
Nicholas E. Comben ◽  
Alistair M. Hetherington ◽  
Antony N. Dodd

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xin Jia ◽  
Ke Mao ◽  
Ping Wang ◽  
Yu Wang ◽  
Xumei Jia ◽  
...  

AbstractWater deficit is one of the major limiting factors for apple (Malus domestica) production on the Loess Plateau, a major apple cultivation area in China. The identification of genes related to the regulation of water use efficiency (WUE) is a crucial aspect of crop breeding programs. As a conserved degradation and recycling mechanism in eukaryotes, autophagy has been reported to participate in various stress responses. However, the relationship between autophagy and WUE regulation has not been explored. We have shown that a crucial autophagy protein in apple, MdATG8i, plays a role in improving salt tolerance. Here, we explored its biological function in response to long-term moderate drought stress. The results showed that MdATG8i-overexpressing (MdATG8i-OE) apple plants exhibited higher WUE than wild-type (WT) plants under long-term moderate drought conditions. Plant WUE can be increased by improving photosynthetic efficiency. Osmoregulation plays a critical role in plant stress resistance and adaptation. Under long-term drought conditions, the photosynthetic capacity and accumulation of sugar and amino acids were higher in MdATG8i-OE plants than in WT plants. The increased photosynthetic capacity in the OE plants could be attributed to their ability to maintain optimal stomatal aperture, organized chloroplasts, and strong antioxidant activity. MdATG8i overexpression also promoted autophagic activity, which was likely related to the changes described above. In summary, our results demonstrate that MdATG8i-OE apple lines exhibited higher WUE than WT under long-term moderate drought conditions because they maintained robust photosynthesis, effective osmotic adjustment processes, and strong autophagic activity.


Forests ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 14 ◽  
Author(s):  
Maricar Aguilos ◽  
Clément Stahl ◽  
Benoit Burban ◽  
Bruno Hérault ◽  
Elodie Courtois ◽  
...  

Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern driven by Rg, with maximum values for ET in July and August and for WUE at the beginning of the year. By removing radiation effects during water depleted periods, we showed that soil water stress strongly reduced ET. In contrast, drought conditions enhanced radiation-normalized WUE in almost all the years, suggesting that the lack of soil water had a more severe effect on ecosystem evapotranspiration than on photosynthesis. Our results are of major concern for tropical ecosystem modeling because they suggest that under future climate conditions, tropical forest ecosystems will be able to simultaneously adjust CO2 and H2O fluxes. Yet, for tropical forests under future conditions, the direction of change in WUE at the ecosystem scale is hard to predict, since the impact of radiation on WUE is counterbalanced by adjustments to soil water limitations. Developing mechanistic models that fully integrate the processes associated with CO2 and H2O flux control should help researchers understand and simulate future functional adjustments in these ecosystems.


2012 ◽  
Vol 59 (No. 1) ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
W. Liu ◽  
Q. Xue ◽  
T. Dang ◽  
C. Gao ◽  
...  

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20–60 cm, increased water recharge by 16–21 mm, and decreased ASWS by 89–133 mm in 0–300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246–1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was < 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.


Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 110 ◽  
Author(s):  
Andreas Ropokis ◽  
Georgia Ntatsi ◽  
Constantinos Kittas ◽  
Nikolaos Katsoulas ◽  
Dimitrios Savvas

In areas characterized by mild winter climate, pepper is frequently cultivated in unheated greenhouses in which the temperature during the winter may drop to suboptimal levels. Under low temperature (LT) conditions, the uptake of nutrients may be altered in a different manner than that of the water and thus their uptake ratio, known as uptake concentration, may be different than in greenhouses with standard temperature (ST) conditions. In the present study, pepper plants of the cultivars “Sammy” and “Orangery”, self-grafted or grafted onto two commercial rootstocks (“Robusto” and “Terrano”), were cultivated in a greenhouse under either ST or LT temperature conditions. The aim of the study was to test the impact of grafting and greenhouse temperature on total yield, water use efficiency, and nutrient uptake. The LT regime reduced the yield by about 50% in “Sammy” and 33% in “Orangery”, irrespective of the grafting combination. Grafting of “Sammy” onto both “Robusto” and “Terrano” increased the total fruit yield by 39% and 34% compared with the self-grafted control, while grafting of “Orangery” increased the yield only when the rootstock was “Terrano”. The yield increase resulted exclusively from enhancement of the fruit number per plant. Both the water consumption and the water use efficiency were negatively affected by the LT regime, however the temperature effect interacted with the rootstock/scion combination. The LT increased the uptake concentrations (UC) of K, Ca, Mg, N, and Mn, while it decreased strongly that of P and slightly the UC of Fe and Zn. The UC of K and Mg were influenced by the rootstock/scion combination, however this effect interacted with the temperature regime. In contrast, the Ca, N, and P concentrations were not influenced by the grafting combination. The results of the present study show that the impact of grafting on yield and nutrient uptake in pepper depend not merely on the rootstock genotype, however on the rootstock/scion combination.


2006 ◽  
Vol 26 (7) ◽  
pp. 2079-2086 ◽  
Author(s):  
Fengjun Zhao ◽  
Yingbai Shen ◽  
Rongfu Gao ◽  
Xiaohua Su ◽  
Bingyu Zhang

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Milan Borišev ◽  
Rita Horak ◽  
Slobodanka Pajević ◽  
Saša Orlović ◽  
Nataša Nikolić ◽  
...  

AbstractThe paper presents the impact of periodic soil drought on physiological parameters important for bioproductivity of mountain beech populations. The investigated forest population was located near Fruška gora mountain peak, where water runs off quickly, and consequently lack of soil humidity develops very often. Decreasing trends of photosynthesis, transpiration, water use efficiency and stomatal conductance (gs) during the growing season were evident, in correlation with a shortage of precipitation. Diurnally, photosynthesis of beech leaves showed rhythmical changes. It was the most intensive in the morning, then decreased between noon and 1 pm, and increased again during early afternoon. High leaf temperature and water deficit in the deeper soil layers caused a decreasing trend in photosynthesis and daily rhythmic changes of the transpiration rate and water use efficiency. Although surface soil water capacity did not show a significant decreasing trend from July to September, a lack of precipitation was observed, which probably caused a lack of moisture in deeper soil layers, resulting in a decline in photosynthesis and transpiration. Physiological status, linked to primary photosynthetic productivity of forests, could be a significant indicator of environmental conditions and trends in climate changes.


Sign in / Sign up

Export Citation Format

Share Document