Register      Login
Functional Plant Biology Functional Plant Biology Society
Plant function and evolutionary biology
RESEARCH ARTICLE

Isotopic evidence for nitrogen exchange between autotrophic and heterotrophic tissues in variegated leaves

Cyril Abadie A , Marlène Lamothe-Sibold B , Françoise Gilard B and Guillaume Tcherkez A C
+ Author Affiliations
- Author Affiliations

A Research School of Biology, ANU College of Medicine, Biology and Environment, Australian National University, Canberra, ACT 2601, Australia.

B Université Paris-Sud, Institute of Plant Sciences Paris-Saclay IPS2 (Bâtiment 630), UMR CNRS-INRA 9213, Université Paris-Saclay, 91405 Orsay, France.

C Corresponding author. Email: guillaume.tcherkez@anu.edu.au

Functional Plant Biology 43(3) 298-306 https://doi.org/10.1071/FP15187
Submitted: 7 July 2015  Accepted: 12 November 2015   Published: 12 January 2016

Abstract

Many plant species or cultivars form variegated leaves in which blades are made of green and white sectors. On the one hand, there is little photosynthetic CO2 assimilation in white tissue simply because of the lack of functional chloroplasts and thus, leaf white tissue is heterotrophic and fed by photosynthates exported by leaf green tissue. On the other hand, it has been previously shown that the white tissue is enriched in nitrogenous compounds such as amino acids and polyamines, which can, in turn, be remobilised upon nitrogen deficiency. However, the origin of organic nitrogen in leaf white tissue, including the possible requirement for N-reduction in leaf green tissue before export to white tissue, has not been examined. Here, we took advantage of isotopic methods to investigate the source of nitrogen in the white tissue. A survey of natural isotope abundance (δ15N) and elemental composition (%N) in various variegated species shows no visible difference between white and green tissues, suggesting a common N source. However, there is a tendency for N-rich white tissue to be naturally 15N-enriched whereas in the model species Pelargonium × hortorum, white sectors are naturally 15N-depleted, indicating that changes in metabolic composition and/or N-partitioning may occur. Isotopic labelling with 15N-nitrate on illuminated leaf discs clearly shows that the white tissue assimilates little nitrogen and thus relies on nitrate reduction and metabolism in the green tissue. The N-sink represented by the white tissue is considerable, accounting for nearly 50% of total assimilated nitrate.

Additional keywords: isotopes, labelling, metabolism, N-assimilation, Pelargonium, variegation.


References

Abadie C, Lamothe M, Mauve C, Gilard F, Tcherkez G (2015) Leaf green-white variegation is advantageous under N deprivation in Pelargonium × hortorum. Functional Plant Biology 42, 543–551.
Leaf green-white variegation is advantageous under N deprivation in Pelargonium × hortorum.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXosFGlurY%3D&md5=1f4fa2107134efeff45089602b8d5053CAS |

Aluru MR, Zola J, Foudree A, Rodermel SR (2009) Chloroplast photooxidation-induced transcriptome reprogramming in Arabidopsis immutans white leaf sectors. Plant Physiology 150, 904–923.
Chloroplast photooxidation-induced transcriptome reprogramming in Arabidopsis immutans white leaf sectors.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXnsleitbg%3D&md5=526423a8f8e04622bf27fb91c7963f01CAS | 19386811PubMed |

Borner T (1986) Chloroplast control of nuclear gene function. Endocytobiosis and Cell Research 3, 265–274.

Borner T, Mandel RR, Schiemann J (1986) Nitrate reductase is not accumulated in chloroplast-ribosome-deficient mutants of higher plants. Planta 169, 202–207.
Nitrate reductase is not accumulated in chloroplast-ribosome-deficient mutants of higher plants.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC2c7mvVKqtw%3D%3D&md5=7c8d98f8624de4aac4f9d203466b9c66CAS | 24232551PubMed |

Campitelli BE, Stehlik I, Stinchcombe JR (2008) Leaf variegation is associated with reduced herbivore damage in Hydrophyllum virginianum. Botany 86, 306–313.
Leaf variegation is associated with reduced herbivore damage in Hydrophyllum virginianum.Crossref | GoogleScholarGoogle Scholar |

Chang Q, Chen S, Chen Y, Deng Y, Chen F, Zhang F, Wang S (2013) Anatomical and physiological differences and differentially expressed genes between the green and yellow leaf tissue in a variegated Chrysanthemum variety. Molecular Biotechnology 54, 393–411.
Anatomical and physiological differences and differentially expressed genes between the green and yellow leaf tissue in a variegated Chrysanthemum variety.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXms1GrsL0%3D&md5=d6e8139198ce79a3a846d912016a6d78CAS | 22782702PubMed |

Cohen AS, Popovic RB, Zalik S (1979) Effects of polyamines on chlorophyll and protein content, photochemical activity and chloroplast ultrastructure of barley leaf discs during senescence. Plant Physiology 64, 717–720.
Effects of polyamines on chlorophyll and protein content, photochemical activity and chloroplast ultrastructure of barley leaf discs during senescence.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3cXjsl2mtA%3D%3D&md5=afe8628ac0c413dffb80df8a4ffc009eCAS | 16661041PubMed |

Esteban R, Fernendez-Marin B, Becerril JM, Garcia-Plazaola JI (2008) Photoprotective implications of leaf variegation in E. dens-canis L. and P. officinalis L. Journal of Plant Physiology 165, 1255–1263.
Photoprotective implications of leaf variegation in E. dens-canis L. and P. officinalis L.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtFeiu7nO&md5=a934f243fa6d121cd1bca6bb3c79c2a6CAS | 18180073PubMed |

Evenari M (1989) The history of research on white-green variegated plants. Botanical Review 55, 106–139.
The history of research on white-green variegated plants.Crossref | GoogleScholarGoogle Scholar |

Foudree A, Putarjunan A, Kambakam S, Nolan T, Fussell J, Pogorelko G, Rodermel S (2012) The mechanism of variegation in immutans provides insight into chloroplast biogenesis. Frontiers in Plant Science 3, 260
The mechanism of variegation in immutans provides insight into chloroplast biogenesis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhtFWisLvK&md5=a4b4711dcd849f04a88b31cc8f4343b9CAS | 23205022PubMed |

Gaufichon L, Masclaux-Daubresse C, Tcherkez G, Reisdorf-Cren M, Sakakibara Y, Hase T, Clément G, Avice JC, Granjean O, Marmagne A, Boutet-Mercey S, Azzopardi M, Soulay F, Suzuki A (2013) Arabidopsis thaliana Asn2 encoding asparagine synthetase is involved in the control of nitrogen assimilation and export during vegetative growth. Plant, Cell & Environment 36, 328–342.
Arabidopsis thaliana Asn2 encoding asparagine synthetase is involved in the control of nitrogen assimilation and export during vegetative growth.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXjslWhtw%3D%3D&md5=a26f50bf2e580b10787fb44fd9dcd602CAS |

Gauthier PG, Lamothe M, Mahé A, Molero G, Nogués S, Hodges M, Tcherkez G (2013) Metabolic origin of δ15N values in nitrogenous compounds from Brassica napus L. leaves. Plant, Cell & Environment 36, 128–137.
Metabolic origin of δ15N values in nitrogenous compounds from Brassica napus L. leaves.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhsl2lsr3I&md5=9bf34adc37a9a2e004f653e9c5f2deeaCAS |

Givnish TJ (1990) Leaf mottling: relation to growth form and leaf phenology and possible role as camouflage. Functional Ecology 4, 463–474.
Leaf mottling: relation to growth form and leaf phenology and possible role as camouflage.Crossref | GoogleScholarGoogle Scholar |

Hu F, Zhu Y, Wu W, Xie Y, Huang J (2015) Leaf variegation of thylakoid formation 1 is suppressed by mutations of specific sigma factors in Arabidopsis. Plant Physiology 168, 1066–1075.
Leaf variegation of thylakoid formation 1 is suppressed by mutations of specific sigma factors in Arabidopsis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXht1eiu7bN&md5=7aefef52145645acaf9ecc26b7e9d2beCAS | 25999408PubMed |

Kato Y, Miura E, Ido K, Ifuku K, Sakamoto W (2009) The variegated mutants lacking chloroplastic FtsHs are defective in D1 degradation and accumulate reactive oxygen species. Plant Physiology 151, 1790–1801.
The variegated mutants lacking chloroplastic FtsHs are defective in D1 degradation and accumulate reactive oxygen species.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsFOgtr3F&md5=4ce703caf41e51ab4f234e5fd069dcf0CAS | 19767385PubMed |

Lev-Yadun S (2014) Potential defence from herbivory by ‘dazzle effects’ and ‘trickery coloration’ of leaf variegation. Biological Journal of the Linnean Society. Linnean Society of London 111, 692–697.
Potential defence from herbivory by ‘dazzle effects’ and ‘trickery coloration’ of leaf variegation.Crossref | GoogleScholarGoogle Scholar |

Lev-Yadun S (2015) The proposed anti-herbivory roles of white leaf variegation. Progress in Botany 76, 241–269.
The proposed anti-herbivory roles of white leaf variegation.Crossref | GoogleScholarGoogle Scholar |

Powikrowska M, Khrouchtchova A, Martens HJ, Zygadlo-Nielsen A, Melonek J, Schulz A, Krupinska K, Rodermel S, Jensen PE (2014) SVR4 (suppressor of variegation 4) and SVR4-like: two proteins with a role in proper organization of the chloroplast genetic machinery. Physiologia Plantarum 150, 477–492.
SVR4 (suppressor of variegation 4) and SVR4-like: two proteins with a role in proper organization of the chloroplast genetic machinery.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXitFWhu74%3D&md5=938aebc99746f163512c60f09de03e9fCAS | 24111559PubMed |

Pringsheim EG, Schwarz W (1933) Das Auftretenweissbunter(panaschierter) Pflanzen in der Natur. Flora 28, 111–122.

Putarjunan A, Rodermel S (2014) gigantean suppresses immutans variegation by interactions with cytokinin and gibberellin signaling pathways. Plant Physiology 166, 2115–2132.
gigantean suppresses immutans variegation by interactions with cytokinin and gibberellin signaling pathways.Crossref | GoogleScholarGoogle Scholar | 25349324PubMed |

Rosso D, Bode R, Li W, Krol M, Saccon D, Wang S, Schillaci LA, Rodermel SR, Maxwell DP, Hüner NPA (2009) Photosynthetic redox imbalance governs leaf sectoring in the Arabidopsis thaliana variegation mutants immutans, spotty, var1 and var2. The Plant Cell 21, 3473–3492.
Photosynthetic redox imbalance governs leaf sectoring in the Arabidopsis thaliana variegation mutants immutans, spotty, var1 and var2.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXovVWrtQ%3D%3D&md5=9e968b6b20e324da50efa3d233e53236CAS | 19897671PubMed |

Sawhney SK, Prakash V, Naik MS (1972) Nitrate reductase and nitrite reductase activities in induced chlorophyll mutants of barley. FEBS Letters 22, 200–202.
Nitrate reductase and nitrite reductase activities in induced chlorophyll mutants of barley.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE38XksFyrurs%3D&md5=c49d720ea9ac4ebb1f530b6935d5fc50CAS | 11946596PubMed |

Seltmann H (1955) Comparative physiology of green and albino corn seedlings. Plant Physiology 30, 258–263.
Comparative physiology of green and albino corn seedlings.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaG2MXosFWguw%3D%3D&md5=8eeb925368ac556f005dc9a97ea71f44CAS | 16654766PubMed |

Smith AP (1986) Ecology of a leaf color polymorphism in a tropical forest species: habitat segregation and herbivory. Oecologia 69, 283–287.
Ecology of a leaf color polymorphism in a tropical forest species: habitat segregation and herbivory.Crossref | GoogleScholarGoogle Scholar |

Smith HB (1999) Photosynthetic pigmentation – variegation on a theme. The Plant Cell 11, 1–3.
Photosynthetic pigmentation – variegation on a theme.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXhtVGrsL0%3D&md5=cbf63d4d229385462be3959b244cf3a7CAS | 9878627PubMed |

Tcherkez G (2011) Natural 15N/14N isotope composition in C3 leaves: are enzymatic isotope effects informative for predicting the 15N-abundance in key metabolites? Functional Plant Biology 38, 1–12.
Natural 15N/14N isotope composition in C3 leaves: are enzymatic isotope effects informative for predicting the 15N-abundance in key metabolites?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsFynurrE&md5=f9f1f6773b2b9037a27df05a3f27fbe6CAS |

Tcherkez G, Hodges M (2008) How stable isotopes may help to elucidate primary nitrogen metabolism and its interactions with (photo)respiration in C3 leaves. Journal of Experimental Botany 59, 1685–1693.
How stable isotopes may help to elucidate primary nitrogen metabolism and its interactions with (photo)respiration in C3 leaves.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXmtleltbo%3D&md5=781f6e9635e2caed390c3f70b7ab34b2CAS | 17646207PubMed |

Tcherkez G, Mauve C, Lamothe M, Le Bras C, Grapin A (2011) The 13C/12C isotopic signal of day-respired CO2 in variegated leaves of Pelargonium × hortorum. Plant, Cell & Environment 34, 270–283.
The 13C/12C isotopic signal of day-respired CO2 in variegated leaves of Pelargonium × hortorum.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXisVGjsb8%3D&md5=9bdaffda3d45d2eecaa7e7fcc1828eeeCAS |

Tcherkez G, Guérard F, Gilard F, Lamothe M, Mauve C, Gout E, Bligny R (2012) Metabolomic characterization of the functional division of nitrogen metabolism in variegated leaves. Functional Plant Biology 39, 959–967.
Metabolomic characterization of the functional division of nitrogen metabolism in variegated leaves.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhslKru7%2FN&md5=135fc9d586e14a87e09277db6f321fd5CAS |

Urbanczyk-Wochniak E, Fernie AR (2005) Metabolic profiling reveals altered nitrogen nutrient regimes have diverse effects on the metabolism of hydroponically-grown tomato (Solanum lycopersicum) plants. Journal of Experimental Botany 56, 309–321.
Metabolic profiling reveals altered nitrogen nutrient regimes have diverse effects on the metabolism of hydroponically-grown tomato (Solanum lycopersicum) plants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXkt1WltQ%3D%3D&md5=905c1c3eb6e8e4e3f840389ed2949eeaCAS | 15596475PubMed |

Werner RA, Schmidt HL (2002) The in vivo nitrogen isotope discrimination among organic plant compounds. Phytochemistry 61, 465–484.
The in vivo nitrogen isotope discrimination among organic plant compounds.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xot1Wmu70%3D&md5=5190ee4a4289d49939363b8fc98a02eeCAS | 12409013PubMed |

Yu FEI, Fu A, Aluru M, Park S, Xu Y, Liu H, Rodermel S (2007) Variegation mutants and mechanisms of chloroplast biogenesis. Plant, Cell & Environment 30, 350–365.
Variegation mutants and mechanisms of chloroplast biogenesis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjtlemu7k%3D&md5=90c22fb95d24a82152c596dc1a432b30CAS |