The role of nitrogen in photosynthetic acclimation to elevated [CO 2 ] in tomatoes

Moshe Halpern, Asher Bar-Tal, Nitsan Lugassi, Aiman Egbaria, David Granot, Uri Yermiyahu

Research output: Contribution to journalArticlepeer-review

31 Scopus citations

Abstract

Background: Although elevated [CO 2 ] causes an increase of photosynthesis in the short-term, this increase is often attenuated over time due to decreased photosynthetic capacity of the leaf in a process called photosynthetic acclimation to elevated CO 2 (PAC). PAC is often accompanied by N deficiency and sink:source imbalance. The aim of this study is to investigate mechanisms that lead to PAC, N deficiency and sink:source imbalance in tomato plants grown in elevated [CO 2 ] and how they are affected by different levels of N treatments. Methods: Two long-term experiment and two short-term experiments were conducted in which tomato plants were grown in chambers with ambient [CO 2 ] and elevated [CO 2 ] combined with different levels of N nutrition. The following parameters were measured: 1) Biomass 2)Leaf N, P and K concentrations, 3) leaf NO 3 concentration, 4) Gas exchange 5) Rubisco expression and 6) Leaf starch concentration. Results: Plants grown at e[CO 2 ] had increased biomass and starch, and decreased gas exchange, stomatal conductivity, Rubisco expression, V cmax , NPK and leaf NO 3 . Increasing N fertilization counteracted many of the effects of elevated [CO 2 ]. Conclusions: PAC was caused by decreased N uptake or transport coupled with increased growth which leads to N deficiency and a sink:source imbalance. Increased N fertilization counteracted the effect of e[CO 2 ] on photosynthesis, N status, and sink:source imbalance. Furthermore, elevated [CO 2 ] caused stomata to partially close, which accounted for some of the PAC observed.

Original languageEnglish
Pages (from-to)397-411
Number of pages15
JournalPlant and Soil
Volume434
Issue number1-2
DOIs
StatePublished - 15 Jan 2019
Externally publishedYes

Keywords

  • Carbon dioxide
  • Nitrogen assimilation
  • Nitrogen uptake
  • Photosynthesis
  • Sink:Source
  • Stomata

ASJC Scopus subject areas

  • Soil Science
  • Plant Science

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