Isolation and characterization of a novel cadmium-regulated Yellow Stripe-Like transporter (SnYSL3) in Solanum nigrum

Abstract

SnYSL3 encodes a plasma-localized transporter delivering various metal-nicotianamine complexes. The expression of SnYSL3 is up-regulated by excess Cd, suggesting an important role for SnYSL3 in response to Cd stress. The Yellow Stripe-Like (YSL) transporters have been proposed to participate in metal uptake and long-range transport in model plants. In this study, we isolated and characterized a novel member of the YSL gene family, SnYSL3, from the cadmium hyperaccumulator Solanum nigrum. SnYSL3 was constitutively expressed and encodes a plasma membrane-localized protein. In situ RNA hybridization localized the SnYSL3 transcripts predominantly in vascular tissues and epidermal cells of the roots and stems, while in leaves, the mRNA levels were high in the vasculature. The SnYSL3 expression level was up-regulated by excess Cd, excess Fe and Cu deficiency. Heterologous expression of SnYSL3 in yeast revealed that SnYSL3 transports nicotianamine complexes containing Fe(II), Cu, Zn and Cd. SnYSL3 overexpression in Arabidopsis thaliana decreased Fe and Mn concentrations in the roots and increased the root-to-shoot translocation ratios of Fe and Mn. Under Cd exposure, the transgenic plants showed increased translocation ratios of Fe and Cd, but no difference was observed in Mn translocation from roots to shoots between the transgenic and wild-type lines. Although the accurate function of SnYSL3 remains to be confirmed, these results suggest that SnYSL3 is a transporter delivering a broad range of metal-nicotianamine complexes and is potentially important for the response to heavy metal stress, especially due to Cd and Fe.

Physiological and transcriptome response to cadmium in cosmos (Cosmos bipinnatus Cav.) seedlings

“…Cd mediated the expression of YSL3 and YSL7 , suggesting Cd affected Fe transport in the plant. Previous study also found that YSL3 in Solanum nigrum and YSL7 in Brassica juncea were induced by Cd as well 58 , 59 . However, it remains unknown whether YSL family genes are involved in transport of Cd-NA complexes transport, and further study must be conducted to analyze the function of YSL genes under Cd stress.…”

Reducing Cadmium Accumulation in Plants: Structure–Function Relations and Tissue-Specific Operation of Transporters in the Spotlight

“…Cadmium is a non-essential element; thus, plants have not developed a specialized uptake system for its absorption. Instead, Cd enters plants and is transported across various membranes by other metal transporters [40][41][42][43] or non-selective cation channels [44,45]. This results in a competition with acquisition of some essential metals.…”

“…Here, Fe(III)-phytosiderophore complexes (Fe(III)-PS) are taken into the root cells by yellow stripe 1 or yellow stripe-like 1 (YS1/YSL1) transporters identified in maize [75] and barley [76]. In chelated form, Cd may also be transported by YSL (yellow stripe-like 1) proteins such as OsYSL2 in rice and SnYSL3 in Solanum nigrum [41,77]. Plants belonging to Strategy I have the ability to transport Cd across plasma membrane by the same mechanisms employed for Fe 2+ transport.…”

“…Of all the transporters above, NRAMP members have been demonstrated to be involved in numerous functions including uptake, translocation, intracellular transport, and detoxification of transition metals in many species [41,71,[79][80][81][82][83]. In rice, OsNRAMP5, which plays a major role in Mn 2+ uptake, may also represent a major route of Cd uptake by roots [73,82].…”

In silico identification and expression analysis of Metal-nicotianamine transporter (YSL3) and Oligopeptide transporter 3 (OPT3) under Cd stress in Brassica oleracea var. acephala

“…According to Feng et al (2017), Metal-nicotianamine transporter 3 (YSL 3 ) gene expression increased significantly in response to excess cadmium in Solanum nigrum. On the other hand, the response of genes to metal-deficient, metalsufficient or metal-excess conditions is partially depending on the plant species (Morkunas et al 2018).…”