Genome-wide analysis and expression profiling of the PIN auxin transporter gene family in soybean (Glycine max)

Abstract

BackgroundThe plant phytohormone auxin controls many aspects of plant growth and development, which largely depends on its uneven distribution in plant tissues. Transmembrane proteins of the PIN family are auxin efflux facilitators. They play a key role in polar auxin transport and are associated with auxin asymmetrical distribution in plants. PIN genes have been characterized in several plant species, while comprehensive analysis of this gene family in soybean has not been reported yet.ResultsIn this study, twenty-three members of the PIN gene family were identified in the soybean genome through homology searches. Analysis of chromosome distribution and phylogenetic relationships of the soybean PIN genes indicated nine pairs of duplicated genes and a legume specific subfamily. Organ/tissue expression patterns and promoter activity assays of the soybean PINs suggested redundant functions for most duplicated genes and complementary and tissue-specific functions during development for non-duplicated genes. The soybean PIN genes were differentially regulated by various abiotic stresses and phytohormone stimuli, implying crosstalk between auxin and abiotic stress signaling pathways. This was further supported by the altered auxin distribution under these conditions as revealed by DR5::GUS transgenic soybean hairy root. Our data indicates that GmPIN9, a legume-specific PIN gene, which was responsive to several abiotic stresses, might play a role in auxin re-distribution in soybean root under abiotic stress conditions.ConclusionsThis study provided the first comprehensive analysis of the soybean PIN gene family. Information on phylogenetic relationships, gene structure, protein profiles and expression profiles of the soybean PIN genes in different tissues and under various abiotic stress treatments helps to identity candidates with potential roles in specific developmental processes and/or environmental stress conditions. Our study advances our understanding of plant responses to abiotic stresses and serves as a basis for uncovering the biological role of PIN genes in soybean development and adaption to adverse environments.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2149-1) contains supplementary material, which is available to authorized users.

Genome-wide identification and expression profiling of the PIN auxin transporter gene family in L. chinense

“…In Arabidopsis thaliana, the PIN3/4/7 family underwent an extensive differentiation in comparison to other plant species, indicating that AtPIN3/4/7 may have undergone functional speci cation in this species. The PIN6 group could not be identi ed in monocotyledons, consistent with previous studies [25]. The PIN3 and PIN10 subfamilies are exclusive to dicots and monocots respectively and may have evolved independently in these lineages, based on previous studies [10,25].…”

“…The PIN6 group could not be identi ed in monocotyledons, consistent with previous studies [25]. The PIN3 and PIN10 subfamilies are exclusive to dicots and monocots respectively and may have evolved independently in these lineages, based on previous studies [10,25]. Since previous studies found that magnoliaceae emerged before the divergence of monocotyledons and dicotyledons, this suggests that in monocotyledons the PIN3 and PIN6 families were lost, while the PIN10 family evolved independently.…”

“…In order to better understand the diversity and similarity of the LcPIN genes, we analyzed their intron-exon structure (Fig 2B & Additional le 1), nding little variation overall. The main reason for gene length variation is the variation in intron length, which was also found for other species [25].…”

“…With the release of genome data for different species, the PIN gene family so far has been identi ed in a variety of living multicellular plants, such as rice, maize, cotton, soybeans, etc. [24][25][26][27]. Transcriptome data analysis and qRT-PCR showed that there might be functional interactions and redundancy between PIN genes, which also play a role in abiotic stress response and interaction with other plant hormones [27,28].…”

Genome-wide identification and expression analysis of ClLAX, ClPIN and ClABCB genes families in Citrullus lanatus under various abiotic stresses and grafting

“…In soybean, abiotic stress and hormonal treatments altered auxin accumulation and distribution in the roots. In addition, under these conditions, some GmPIN genes might contribute to auxin distribution and homeostasis [68]. In rice, overexpression of OsPIN3t improved drought tolerance and knockdown of OsPIN3t led to insensitive to drought stress [36].…”