Molecular characterization of Fe-acquisition genes causing decreased Fe uptake and photosynthetic inefficiency in Fe-deficient sunflower

Abstract

Iron (Fe) deficiency in plants hinders growth and yield. Thus, this study aims to elucidate the responses and molecular characterization of genes in Fe-deficient sunflower. The study was conducted on 14 days-old sunflower plants cultivated in hydroponic culture under Fe-sufficient and Fe-deficient conditions. The Fe-starved sunflower showed substantial decrease in plant biomass, SPAD score, quantum yield efficiency of PSII (Fv/Fm), photosynthetic performance index (Pi_ABS). Further, Fe shortage reduced Fe and Zn concentrations in roots and shoots, accompanied by a marked decrease of HaNramp1 and HaZIP1 expression in roots, suggesting the association of Zn status contributing to photosynthetic inefficiency in sunflower. The ferric chelate reductase (FCR) activity, along with HaFRO2 and HaIRT1 transcripts, were constitutively expressed, suggesting that sunflower plants can regulate FCR activity, although the lack of bioavailable Fe in the rhizosphere strongly corresponds to the limited Fe uptake in sunflower. The substantial increase of proton extrusion in roots and the localization of Fe-related genes in the plasma membrane are also evident in sunflower as common responses to Fe-deficiency by this Strategy I plant species. Analysis showed that three motifs of Fe-related proteins were linked to the ZIP zinc transporter. The interactome map revealed the close partnership of these Fe-related genes in addition to FRU gene encoding putative transcription factor linked to Fe uptake response. The cis-regulatory analysis of promoter suggested the involvement of auxin, salicylic acid, and methyl jasmonate-responsive elements in the regulatory process in response to Fe deficiency. These findings may be beneficial to develop Fe-efficient sunflower plants through breeding or genome editing approaches.

Modulation of photosynthesis under salinity and the role of mineral nutrients in Jatropha curcas L.

“…These data suggest that Fe stress decreases the photochemical capacity and Chl per unit area accompanied by a reduction in the number of grana and stroma lamellae per chloroplast and by a reduction in the number of thylakoids per granum (Dorta‐Santos et al, 2020; Elkhouni et al, 2018; Osório et al, 2014). Kabir et al (2021) described that Fe shortage reduced Fe and Zn concentrations in roots and shoots, accompanied by a marked decrease of HaNramp1 and HaZIP1 expression in roots, suggesting the association of Zn status contributing to photosynthetic inefficiency.…”

Genome-wide identification of the ZIP gene family in lettuce (Lactuca sativa L.) and expression analysis under different element stress

“…The LsZIP gene family contains cis-acting elements that respond to hormones and stress, such as methyl jasmonate, abscisic acid, auxin, and salicylic acid. In a previous study, Akther [ 48 ] found that tolerance to Zn deficiency in tomato is dependent on auxin signaling; Song [ 49 ] found that ABA can reduce Zn uptake and accumulation in grapes by inducing ZIP gene expression; furthermore, Kabir [ 50 ] found that salicylate and methyl jasmonate response elements in three ZIP genes of sunflower were regulated in response to iron deficiency; Matsuoka [ 51 ] found that erythromycin positively regulated AtZIP1 expression under iron sufficiency or iron deficiency conditions. This suggests that LsZIP gene expression may be induced by several plant hormones, such as salicylic acid, MeJA, abscisic acid, gibberellin, and auxin.…”

Exploring Aluminum Tolerance Mechanisms in Crops: A Comprehensive Review of Genetic, Metabolic, and Physiological Adaptations in Acidic Soils

“…The ROS otherwise would be an inducer for different genes related to Al tolerance most specifically synthesis of organic acids. The organic acids in turn are also induced by some growth regulators like ethylene under Al stress [141] Ethylene in wheat has also been reported with negative control for Al activated malate transporter (ALMT1) that reduces the root secretion of organic acids. Thereby, mutation of this gene would be sufficient for sensitive to Al toxicity [142].…”