Open Access

ARTICLE

Overexpression of the LcPIN2 and LtPIN2 Gene in Arabidopsis thaliana Promotes Root Elongation

by Zijian Cao^#, Guoxia Xue^#, Lingfeng Hu, Haoxian Qu, Shuang Liang, Jisen Shi, Jinhui Chen^*, Zhaodong Hao^*

Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China

* Corresponding Authors: Jinhui Chen. Email: ; Zhaodong Hao. Email:

Phyton-International Journal of Experimental Botany 2023, 92(8), 2383-2397. https://doi.org/10.32604/phyton.2023.029845

Received 10 March 2023; Accepted 26 April 2023; Issue published 25 June 2023

Abstract

The auxin polar transporter, PIN-FORMED 2 (PIN2) plays an important role in root development. However, it remains unclear whether PIN2 genes form two Liriodendron species, L. chinense (LcPIN2) and L. tulipifera (LtPIN2), are both involved in root development and whether and to what extent these two genes diverge in function. Here, we cloned and overexpressed LcPIN2 and LtPIN2 in Arabidopsis thaliana wild-type (WT) and Atpin2 mutant. Phylogenetic and sequence analysis showed a small degree of differentiation between these two Liriodendron PIN2 genes. Tissue-specific gene expression analysis indicated that both Liriodendron PIN2 genes were highly expressed in roots, implying a potential role in root development. Finally, heterologous overexpression of LcPIN2 and LtPIN2 in Arabidopsis both significantly increased the root length compared to wild-type and empty vector. Furthermore, the root length defect in Atpin2 was complemented both by LcPIN2 and LtPIN2. However, heterologous overexpression of LcPIN2 and LtPIN2 cannot rescue the defect in root gravitropism of Atpin2 mutants. Taken together, our findings unravel PIN2 genes from the magnoliids plant Liriodendron were functionally conserved with AtPIN2 in the dicotyledonous plant Arabidopsis in regard to the regulation of root length, but not root gravitropism. This study also provides a potential target for genetic improvement of the root system in these valuable forest trees Liriodendron.

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