Genome‐wide identification and expression analysis of Polyamine Uptake Transporter gene family in sweet orange (Citrus sinensis)

Abstract

Polyamine uptake transporter (PUT) plays important roles in polyamine homeostasis, but knowledge regarding PUT family genes in sweet orange (Citrus sinensis) remains elusive.• Herein, our study aimed to perform a genome-wide identification of the PUT gene family in C. sinensis. A total of eight putative PUT genes (CsPUT1-CsPUT8) were identified in the sweet orange genome and distributed on three chromosomes. The CsPUT genes were divided into two major groups according to the phylogenetic tree analysis, with high similarities in protein domains and gene structure organization.• The CsPUT genes were differentially expressed in different tissues, with the highest transcript levels being in the flowers and roots. Interestingly, the CsPUT genes were significantly induced by polyamines, putrescine, spermidine and spermine, indicating that CsPUT were possibly associated with intracellular polyamine transport and uptake. In addition, CsPUT showed differential expression in callus treated with ABA, cold, salt or osmotic shock. • CsPUT4 was selected as a candidate for functional analysis of PUT. Overexpression of CsPUT4 elevated endogenous polyamine content and led to enhanced cold tolerance in transgenic callus cultures. Overall, these data provide valuable information for better understanding the potential biological functions of PUT genes in future.

Disruption of three polyamine uptake transporter genes in rice by CRISPR/Cas9 gene editing confers tolerance to herbicide paraquat

“…OsPUT1/2/3 were previously shown to transport polyamines and paraquat in yeast cells (Mulangi et al 2012a , b ). Our current results have demonstrated that genetic editing of OsPUTs could be useful for producing paraquat-resistant rice plants, since the OsPUTs triple mutant plants were tolerant to paraquat with the spray concentration up to 200 μM, a concentration higher than that used by farmers (approximately 140 μM) (Alhag et al 2021 ; Li et al 2013 ). Previously, loss-of-function of AtPAR1 and knock-down expression of OsPAR1/OsPTU3 has been shown to increase paraquat resistance in Arabidopsis and rice, respectively (Li et al 2013 ).…”

“…Our results showed the application potential to create paraquat-resistant transgenic-free rice plants. Since the PUT proteins are very conserved across different plant species (Alhag et al 2021 ; Mulangi et al 2012b ), precise editing of PUT genes is also promising for engineering other crops for weed control.…”