Characterization of wheat miRNAs and their target genes responsive to cadmium stress

Abstract

A increasing number of microRNAs have been shown to play important regulatory roles in plant responses to various metal stresses. However, little information about miRNAs especially miRNAs responsive to cadmium (Cd) stress is available in wheat. To investigate the role of miRNAs in responses to Cd stress, wheat seedlings were subjected to 250 μM Cd solution for 6, 12, 24 and 48 h, and analyses of morphological and physiological changes as well as the expression of five miRNAs and their corresponding targets were carried out. Our results demonstrated that miRNAs and their targets were differentially expressed in leaves and roots of wheat seedlings exposed to Cd stress. Furthermore, miR398 may involve in oxidative stress tolerance by regulating its target CSD to participate in Cd stress. Among ten miRNA-target pairs studied, nine pairs showed complex regulation relationship in leaves and roots of wheat seedlings exposed to Cd stress. These findings suggested that miRNAs are involved in the mediation of Cd stress signaling responses in wheat. The characterization of the miRNAs and the associated targets in responses to Cd exposure provides a framework for understanding the molecular mechanism of heavy metal tolerance in plants.

Abiotic stress miRNomes in the Triticeae

“…The target preference of conserved and non-conserved miRNAs may also differ. Many conserved miRNAs across monocots and dicots, such as miR156, miR159, or miR164, have been shown to target stress-associated transcription factors such as MYB and NAC family members (Gupta et al 2014; Qiu et al 2016). Species and genotype specific miRNA families are more likely to target specific enzymes associated with special pathways than conserved miRNAs.…”

“…When the toxic metal is already present in the cells, plants use storage and detoxification mechanisms including chelation, translocation, or oxidative defense mechanisms (Hall 2002). The role of miRNAs in response to toxic metal stress has been investigated with a few studies reported in the Triticeae (Xu et al 2010; Feng et al 2013; Qiu et al 2016). Cd is one of the most toxic heavy metals for plants.…”

“…Cd inhibits the reproduction of cells both in roots and stems along with a decrease in chlorophyll content. Several miRNAs have been detected in response to Cd stress and underlined as potential regulators of the Cd stress response (Xu et al 2010; Qiu et al 2016). Downregulation of miR156, miR159, miR164, miR398, and miR408 was observed under Cd stress while their targets were mostly upregulated.…”

“…Most of these studies have focused on drought stress although some studies have also been performed on more specific stresses such as UV and heavy metal stresses (Wang et al 2013; Qiu et al 2016) (Fig. 1a).…”

In Vitro Antifungal Activity of Different Plant Hormones on the Growth and Toxicity of Nigrospora Spp. on Date Palm (Phoenix dactylifera L.)

“…The reprogramming of molecular responses (by altering the expression of different genes involved various pathways) consequently stimulated in plant cells in order to restrict the damage caused by a specific stress [10,11].…”