Iron-dependent modifications of the flower transcriptome, proteome, metabolome, and hormonal content in an Arabidopsis ferritin mutant

Abstract

Iron homeostasis is an important process for flower development and plant fertility. The role of plastids in these processes has been shown to be essential. To document the relationships between plastid iron homeostasis and flower biology further, a global study (transcriptome, proteome, metabolome, and hormone analysis) was performed of Arabidopsis flowers from wild-type and triple atfer1-3-4 ferritin mutant plants grown under iron-sufficient or excess conditions. Some major modifications in specific functional categories were consistently observed at these three omic levels, although no significant overlaps of specific transcripts and proteins were detected. These modifications concerned redox reactions and oxidative stress, as well as amino acid and protein catabolism, this latter point being exemplified by an almost 10-fold increase in urea concentration of atfer1-3-4 flowers from plants grown under iron excess conditions. The mutant background caused alterations in Fe–haem redox proteins located in membranes and in hormone-responsive proteins. Specific effects of excess Fe in the mutant included further changes in these categories, supporting the idea that the mutant is facing a more intense Fe/redox stress than the wild type. The mutation and/or excess Fe had a strong impact at the membrane level, as denoted by the changes in the transporter and lipid metabolism categories. In spite of the large number of genes and proteins responsive to hormones found to be regulated in this study, changes in the hormonal balance were restricted to cytokinins, especially in the mutant plants grown under Fe excess conditions.

A high-resolution gene expression map of theArabidopsisshoot meristem stem cell niche

“…This includes genes encoding FERRETIN1 (an ironstorage protein); AILP1 (which responds to aluminium ions), CAX1-LIKE CATION EXCHANGER 1 and 3, a Ca2+/H+ exchanger; ANNEXIN1, a Ca 2+ -dependent protein with peroxidase activity; a vacuolar Ca 2+ -binding protein that responds to cadmium ions and salt stress (Sudre et al, 2013); protein kinases of the SNF1 family (SNRK2.1, SNRK2.2, SNRK2.6); ABI FIVE BINDING PROTEIN4 (AFP4); and MYB15 (Fujii et al, 2011). At the twofold cutoff, AILP1 and AFP4 were not identified as CPEGs.…”

ZINC FINGER OF ARABIDOPSIS THALIANA12 (ZAT12) Interacts with FER-LIKE IRON DEFICIENCY-INDUCED TRANSCRIPTION FACTOR (FIT) Linking Iron Deficiency and Oxidative Stress Responses

“…The role of ROS in Fe response regulation has not been well defined, and it may play multiple roles. Hydrogen peroxide (H 2 O 2 ) is involved in the regulation of ferritins in response to excess Fe to alleviate the oxidative stress in leaves (Ravet et al, 2009;Briat et al, 2010), flowers (Sudre et al, 2013), and roots (Ravet et al, 2012;Reyt et al, 2015). ROS production has also been shown under Fe deficiency in sunflower (Helianthus annuus) and maize (Zea mays; Ranieri et al, 2001;Sun et al, 2007).…”

Cytokinin determines thiol-mediated arsenic tolerance and accumulation in Arabidopsis thaliana

“…Pi-starved plants were then exposed to 30 mM As(V) in liquid medium (-Pi) for 6 h. Fresh samples were collected and frozen in liquid N 2 . Frozen samples (250 mg) were ground in a mortar with liquid N 2 and homogenized with 4 mL precooled (220°C) methanol:water: formic acid (15:4:1, v/v/v Czech Republic) were added (40 mL stock solution of 50 ng/mL of each standard in methanol) and extracted as described (Sudre et al, 2013). CKs were quantified using a High performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) system as described (Sudre et al, 2013).…”

“…Frozen samples (250 mg) were ground in a mortar with liquid N 2 and homogenized with 4 mL precooled (220°C) methanol:water: formic acid (15:4:1, v/v/v Czech Republic) were added (40 mL stock solution of 50 ng/mL of each standard in methanol) and extracted as described (Sudre et al, 2013). CKs were quantified using a High performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) system as described (Sudre et al, 2013). Significant differences (P , 0.05) among treatments were calculated using one-way ANOVA and the Least Significatn Difference Fisher post hoc test.…”