Decoding plant responses to iron deficiency: Is nitric oxide a central player?
Plants respond to iron deprivation by inducing a series of physiological and morphological responses to counteract the nutrient deficiency. These responses include: (i) the acidification of the extracellular medium, (ii) the reduction of ferric ion and (iii) the increased transport of ferrous ion inside of root cells. This iron transport system is present in strategy I plants and is strictly regulated; at low iron concentration the responses are induced whereas upon iron supply they are repressed. The mechanisms related with this process has been extensively studied, however, the specific cellular effectors involved in sensing iron deficiency, the cascade of components participating in signal transduction, and the way iron is metabolized and delivered, are yet poorly understood. Recently, it has been proposed nitric oxide (NO) as a signaling molecule required for plant responses to iron deficiency. NO is produced rapidly in the root epidermis of tomato plants that are growing under iron deficient conditions. Furthermore, it was demonstrated that NO is required for the expression and activity of iron uptake components in roots during iron deprivation. Here we propose and discuss a working hypothesis to understand the way NO is acting in plants responses to iron deficiency. We specifically highlight the cross talk between NO and plant hormones, and the interaction between NO, iron and glutathione for the formation of dinitrosyl iron complexes (DNICs). Finally, a potential role of DNICs in iron mobilization is proposed.
Ramírez
Leonor
L
Instituto de Investigaciones Biológicas (IIB); Facultad de Ciencias Exactas y Naturales; Universidad Nacional de Mar del Plata; Mar del Plata Argentina.
Graziano
Magdalena
M
Lamattina
Lorenzo
L
Plant Cell. 1998 Feb;10(2):267-82
9490749
Protoplasma. 2003 Jun;221(3-4):269-75
12802634
Annu Rev Plant Biol. 2003;54:109-36
14502987
Planta. 2004 Apr;218(6):900-5
14716561
Plant J. 2007 Dec;52(5):949-60
17892445
Nature. 1999 Feb 25;397(6721):694-7
10067892
Planta. 2007 May;225(6):1597-602
17195940
Plant Physiol. 2001 Apr;125(4):2078-84
11299387
Plant Physiol. 2002 Dec;130(4):1852-9
12481068
Proc Natl Acad Sci U S A. 2006 May 16;103(20):7670-5
16679408
Plant Physiol. 2003 Jul;132(3):1241-8
12857806
Proc Natl Acad Sci U S A. 1996 May 28;93(11):5624-8
8643627
Plant Physiol Biochem. 2007 May;45(5):260-1
17466530
Plant Signal Behav. 2006 Jan;1(1):28-33
19521473
Plant Physiol. 2000 Apr;122(4):1109-18
10759506
J Biol Chem. 2004 Jun 4;279(23):24100-7
15056652
J Exp Bot. 2006;57(15):4145-54
17085755
Plant Cell. 2004 Dec;16(12):3400-12
15539473
Annu Rev Plant Biol. 2003;54:183-206
14509968