Fe and Zn stress induced gene expression analysis unraveled mechanisms of mineral homeostasis in common bean (Phaseolus vulgaris L.)

Abstract

Iron (Fe) and zinc (Zn) stress significantly affects fundamental metabolic and physiological processes in plants that results in reduction of plant growth and development. In the present study, common bean variety; Shalimar French Bean-1 (SFB-1) was used as an experimental material. Four different MGRL media i.e. normal MGRL medium (Control), media without Fe (0-Fe), media without Zn (0-Zn) and media with excess Zn (300-Zn) were used for growing seeds of SFB-1 under in vitro condition for three weeks under optimum conditions. Three week old shoot and root tissues were harvested from the plants grown in these four different in vitro conditions and were, subjected to Fe and Zn estimation. Further, extraction of total RNA for differential gene expression of ten candidate genes selected based on our in silico investigation and their classification, phylogeny and expression pattern was unraveled. Expression analysis of three candidate genes (OPT3, NRAMP2 and NRAMP3) in roots revealed possible cross talk among Fe/Zn stress that was further confirmed by observing less accumulation of Fe in roots under both these conditions. However, we observed, higher accumulation of Fe in shoots under 0-Fe condition compared to control that suggests precise sensing for priority based compartmentalization and partitioning leading to higher accumulation of Fe in shoots. Furthermore, the expression analysis of IRT1, FRO1 and Ferritin 1 genes under Fe/Zn stress suggested their role in uptake/transport and signaling of Fe and Zn, whereas the expression of ZIP2, NRAMP1, HA2 and GLP1 genes were highly responsive to Zn in Phaseolus vulgaris. The identified genes highly responsive to Fe and Zn stress condition can be potential candidates for overcoming mineral stress in dicot crop plants.

Combined effect of elevated CO2 and Fe deficiency on common bean metabolism and mineral profile

“…6a and 8). The repression of FRO1 in soybean and IRT1in common bean plants growing under Fe deficiency has been previously reported (Santos et al 2016(Santos et al , 2020Urwat et al 2021). In contrast to Fe limitation, eCO 2 led to a significant decrease in seed Fe levels with the lower productivity being correlated with the lower Fe accumulation.…”

Integrated breeding approaches to enhance the nutritional quality of food legumes

“…More recently, in common bean, Urwat et al (2021) demonstrated, the expression of IRT1 , FRO1 , and Ferritin 1 genes showed an important role in Fe and Zn uptake/transport and signaling under Fe/Zn stress whereas the expression of ZIP2 , NRAMP1 , HA2 , and GLP1 ( Germin-like protein ) genes in Phaseolus vulgaris was highly responsive to Zn uptake ( Figure 2 ).…”

“…Each of these processes is likely governed by a set of genes, many of which are still unknown. Several studies have discovered genes involved in uptake and mobilization of Fe ( Palmer and Guerinot, 2009 ; Xiong et al, 2012 ; Sen Gupta et al, 2017 ) and Zn ( Palmgren et al, 2008 ; Urwat et al, 2021 ) from different parts of plant to the seeds.…”

“…FIGURE 2Gene families involved in translocation and accumulation of Fe 2+ /Zn 2+ in seed of common bean(Urwat et al, 2021). YSL1 and YSL3 genes are involved in unloading minerals to seeds.…”