Ferritins control interaction between iron homeostasis and oxidative stress in Arabidopsis.
Ferritin protein nanocages are the main iron store in mammals. They have been predicted to fulfil the same function in plants but direct evidence was lacking. To address this, a loss-of-function approach was developed in Arabidopsis. We present evidence that ferritins do not constitute the major iron pool either in seeds for seedling development or in leaves for proper functioning of the photosynthetic apparatus. Loss of ferritins in vegetative and reproductive organs resulted in sensitivity to excess iron, as shown by reduced growth and strong defects in flower development. Furthermore, the absence of ferritin led to a strong deregulation of expression of several metal transporters genes in the stalk, over-accumulation of iron in reproductive organs, and a decrease in fertility. Finally, we show that, in the absence of ferritin, plants have higher levels of reactive oxygen species, and increased activity of enzymes involved in their detoxification. Seed germination also showed higher sensitivity to pro-oxidant treatments. Arabidopsis ferritins are therefore essential to protect cells against oxidative damage.
Ravet
Karl
K
Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, UMR 5004 Agro-M/CNRS/INRA/UMII, Bat. 7, 2 Place Viala, 34060 Montpellier Cedex 1, France.
Touraine
Brigitte
B
Boucherez
Jossia
J
Briat
Jean-François
JF
Gaymard
Frédéric
F
Cellier
Françoise
F
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005293:Ferritins / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D018525:Germination; D006706:Homeostasis; D007501:Iron / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D009154:Mutation; D018384:Oxidative Stress; D010788:Photosynthesis; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D018749:RNA, Plant / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018749:RNA, Plant; D017382:Reactive Oxygen Species; C036483:T-DNA; D002245:Carbon Dioxide; D005293:Ferritins; D007501:Iron