Responses of Photosynthesis And Long-Term Water Use Efficiency To Ambient Air Pollution In Urban Roadside Trees

Abstract We conducted on-site studies in Kyoto City, Japan, to evaluate the effect of air pollution by automobile gas exhaust on the leaf photosynthetic functions of four urban roadside tree species. Nitrogen oxides (NO and NO2) are major air pollutants that are related to automobile gas exhaust. The species-specific response of leaf photosynthesis to air pollution was obtained for single-year data, in which at the high air pollution sites, Rhododendron × pulchrum, Rhaphiolepis indica, and Prunus × yedoensis had a higher restriction of maximum photosynthesis (Amax), while the opposite trend was obtained for Ginkgo biloba. When the data were pooled across the years from 2007 to 2019 in R. pulchrum, the dose-dependent effect of NO and NO2 on photosynthesis became obvious, in which they decreased Amax and increased the long-term leaf water use efficiency. A spatial variability map for R. pulchrum showed a lower Amax and higher water use efficiency at the heavy traffic areas in Kyoto City, which suggests that R. pulchrum increased tolerance to air pollution and water stress at the expense of the leaf photosynthesis. This study revealed the importance of the evaluation of the species-specific response of photosynthesis to air pollution for the efficient use of urban trees, even in regions with relatively low atmospheric pollution levels such as < 40 ppb of NO or NO2.

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Leaf characteristics, wood anatomy and hydraulic properties in tree species from contrasting habitats within upper Rio Negro forests in the Amazon region

Journal of Tropical Ecology ◽

10.1017/s0266467409990538 ◽

2010 ◽

Vol 26 (2) ◽

pp. 215-226 ◽

Cited By ~ 11

Author(s):

M. A. Sobrado

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Water Loss ◽

Tree Species ◽

Mixed Forest ◽

High Water ◽

Hydraulic Characteristics ◽

Use Efficiency ◽

Species Specific

Abstract:Leaf blade physical and chemical characteristics, wood composition and anatomy, as well as long-term water-use efficiency and hydraulic characteristics of leaf-bearing terminal branches were assessed in tree species growing in contrasting forests of the Venezuelan Amazonas: mixed forest on oxisol soil and caatinga on podzol soil. Two upper-canopy tree species were selected in each forest, and three individuals per species were tagged for sampling. Leaf nitrogen isotopic signatures (δ15N) were negative and species-specific, which suggests that in species of both forest the N-cycle is closed, and that tree species can withdraw N from a variety of N-pools. Leaf construction costs, dry mass to leaf area ratio, thickness and sclerophylly index tended to increase in microhabitats with lower fertility and large water table fluctuations. The hydraulic characteristics and long-term water use are species-specific and related to the particular conditions of the habitat at the local scale. Ocotea aciphylla (mixed forest) with a combination of low δ13C and high hydraulic sufficiency may maintain high water loss without risk of xylem embolisms. By contrast, Micranda sprucei (slopes of the caatinga forest), had a combination of relatively high hydraulic sufficiency and the highest long-term water-use efficiency, which suggest that embolism risk would be avoided by water loss restriction. Assuming a warmer and drier climate in the future, the species with more conservative water transport and/or better stomatal control would be at lower risk of mortality.

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Overexpression of MdATG8i improves water use efficiency in transgenic apple by modulating photosynthesis, osmotic balance, and autophagic activity under moderate water deficit

Horticulture Research ◽

10.1038/s41438-021-00521-2 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Xin Jia ◽

Ke Mao ◽

Ping Wang ◽

Yu Wang ◽

Xumei Jia ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Deficit ◽

Water Use ◽

Photosynthetic Capacity ◽

Critical Role ◽

Drought Conditions ◽

Moderate Drought ◽

Use Efficiency ◽

Autophagic Activity

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.

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Effects of climate change and local environmental factors on long-term tree water-use efficiency and growth of Pseudolarix amabilis and Cryptomeria japonica in subtropical China

Journal of Soils and Sediments ◽

10.1007/s11368-020-02829-3 ◽

2021 ◽

Author(s):

Tengjiao Liu ◽

Yan Xu ◽

Zhihong Xu ◽

Hongbing Deng

Keyword(s):

Climate Change ◽

Environmental Factors ◽

Water Use Efficiency ◽

Water Use ◽

Cryptomeria Japonica ◽

Subtropical China ◽

Tree Water Use ◽

Use Efficiency

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Long-term yield and water use efficiency under various tillage systems in Mediterranean rainfed conditions

Annals of Applied Biology ◽

10.1111/j.1744-7348.2007.00142.x ◽

2007 ◽

Vol 150 (3) ◽

pp. 293-305 ◽

Cited By ~ 63

Author(s):

C. Cantero-Martínez ◽

P. Angás ◽

J. Lampurlanés

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Tillage Systems ◽

Rainfed Conditions ◽

Use Efficiency

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Soil water cycle and crop water use efficiency after long-term nitrogen fertilization in Loess Plateau

Plant Soil and Environment ◽

10.17221/207/2012-pse ◽

2012 ◽

Vol 59 (No. 1) ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

B. Wang ◽

W. Liu ◽

Q. Xue ◽

T. Dang ◽

C. Gao ◽

...

Keyword(s):

Water Use Efficiency ◽

Soil Water ◽

Water Use ◽

Water Cycle ◽

Triticum Aestivum L ◽

Growing Seasons ◽

Water Recharge ◽

Use Efficiency ◽

N Management

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.

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