Intraspecific variation in leaf growth of wheat (Triticum aestivum) under Australian Grain Free Air CO2 Enrichment (AGFACE): Is it regulated through carbon and/or nitrogen supply?

Thilakarathne, Chamindathee L. and Tausz-Posch, Sabine and Cane, Karen and Norton, Robert M. and Fitzgerald, Glenn J. and Tausz, Michael and Seneweera, Saman (2015) Intraspecific variation in leaf growth of wheat (Triticum aestivum) under Australian Grain Free Air CO2 Enrichment (AGFACE): Is it regulated through carbon and/or nitrogen supply? Functional Plant Biology, 42 (3). pp. 299-308. ISSN 1445-4408

Abstract

Underlying physiological mechanisms of intraspecific variation in growth response to elevated CO2 concentration [CO2] were investigated using two spring wheat (Triticum aestivum L.) cultivars: Yitpi and H45. Leaf blade elongation rate (LER), leaf carbon (C), nitrogen (N) in the expanding leaf blade (ELB, sink) and photosynthesis (A) and C and N status in the last fully expanded leaf blade (LFELB, source) were measured. Plants were grown at ambient [CO2] (∼384molmol-1) and elevated [CO2] (∼550molmol-1) in the Australian Grains Free Air CO2 Enrichment facility. Elevated [CO2] increased leaf area and total dry mass production, respectively, by 42 and 53% for Yitpi compared with 2 and 13% for H45. Elevated [CO2] also stimulated the LER by 36% for Yitpi compared with 5% for H45. Yitpi showed a 99% increase in A at elevated [CO2] but no A stimulation was found for H45. There was a strong correlation (r2≤0.807) between LER of the ELB and soluble carbohydrate concentration in LFELB. In ELB, the highest spatial N concentration was observed in the cell division zone, where N concentrations were 67.3 and 60.6mg g-1 for Yitpi compared with 51.1 and 39.2mg g-1 for H45 at ambient and elevated [CO2]. In contrast, C concentration increased only in the cell division and cell expansion zone of the ELB of Yitpi. These findings suggest that C supply from the source (LFELB) is cultivar dependent and well correlated with LER, leaf area expansion and whole-plant growth response to elevated [CO2].


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published Version restricted in accordance with copyright policy of publisher (CSIRO Publishing)
Faculty / Department / School: No Faculty
Date Deposited: 26 Feb 2015 23:24
Last Modified: 24 Jun 2016 05:17
Uncontrolled Keywords: diurnal regulation of LER; elevated [CO2]; gas exchange; growth analysis; leaf blade elongation rate
Fields of Research : 06 Biological Sciences > 0607 Plant Biology > 060705 Plant Physiology
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070305 Crop and Pasture Improvement (Selection and Breeding)
07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070302 Agronomy
Socio-Economic Objective: B Economic Development > 82 Plant Production and Plant Primary Products > 8205 Winter Grains and Oilseeds > 820507 Wheat
Identification Number or DOI: 10.1071/FP14125
URI: http://eprints.usq.edu.au/id/eprint/26810

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