Characterization of auxin transporter AUX, PIN and PILS gene families in pineapple and evaluation of expression profiles during reproductive development and under abiotic stresses

Abstract

Polar auxin transport in plant is mediated by influx and efflux transporters, which are encoded by AUX/LAX, PIN and PILS genes, respectively. The auxin transporter gene families have been characterized in several species from monocots and eudicots. However, a genome-wide overview of auxin transporter gene families in pineapple is not yet available. In this study, we identified a total of threeAcAUX genes, 12 AcPIN genes, and seven AcPILS genes in the pineapple genome, which were variably located on 15 chromosomes. The exon-intron structure of these genes and properties of deduced proteins were relatively conserved within the same family. Most protein motifs were widespread in the AUX, PIN or PILS proteins, whereas a few motifs were absent in only one or two proteins. Analysis of the expression profiles of these genes elucidated that several genes exhibited either preferential or tissue-specific expression patterns in vegetative and/or reproductive tissues. AcAUX2 was specifically expressed in the early developmental ovules, while AcPIN1b and AcPILS2 were strongly expressed in stamens and ovules. AcPIN9b, AcPILS1, AcPILS6a, 6b and 6c were abundantly expressed in stamens. Furthermore, qRT-PCR results showed that several genes in these families were responsive to various abiotic stresses. Comparative analysis indicated that the genes with close evolutionary relationships among pineapple, rice and Arabidopsis exhibited similar expression patterns. Overexpression of the AcAUX1 in Arabidopsis rescued the phenotype in aux1-T, and resulted in increased lateral roots in WT. These results will provide new insights into auxin transporter genes of pineapple and facilitate our understanding of their roles in pineapple growth and development.

Comparative Expression Profiling of Snf2 Family Genes During Reproductive Development and Stress Responses in Rice

“…The relative expression level was detected by quantitative real time PCR (qRT-PCR) using the Bio-Rad QRT-PCR system (Foster City, CA, United States) and SYBR Premix Ex TaqII (TaKaRa Perfect Real Time; Zhang et al, 2020a ). The qRT-PCR program was: 95°C for 30 s; 40 cycles of annealing at 95°C for 5 s, and extension at 60°C for 35 s; 95°C for 15 s ( Zhang et al, 2020a ; Zhao et al, 2021 ). The rice OsUBQ5 gene was used as an internal control ( Jain et al, 2006 ).…”

Characterization and expression profiling of PIN auxin efflux transporters reveal their role in developmental and abiotic stress conditions in rice

“…Since we treated the rice seedlings for 16 h and thereafter recorded PIN expression, it appears that a longer duration of heat treatment might downregulate PIN expression. Another study by Zhao et al (2021) in pineapple (Ananas comosus) revealed that the expression of AcPIN8 was upregulated under heat stress while AcPIN5a was downregulated. These observations indicate that the PIN expression is very dynamic, and they are differentially regulated in a PIN member-and plant species-dependent manner during heat stress.…”

“…Since we treated the rice seedlings for 16 h and thereafter recorded PIN expression, it appears that a longer duration of heat treatment might downregulate PIN expression. Another study by Zhao et al. (2021) in pineapple ( Ananas comosus ) revealed that the expression of AcPIN8 was upregulated under heat stress while AcPIN5a was downregulated.…”

Red and Blue Light Affect the Formation of Adventitious Roots of Tea Cuttings (Camellia sinensis) by Regulating Hormone Synthesis and Signal Transduction Pathways of Mature Leaves

“…In the study of Arabidopsis, light affects IAA synthesis during seedling germination, and IAA transport from developing leaves to roots ( Bhalerao et al, 2002 ). Auxin transport is usually mediated by auxin influx and efflux vectors, which are encoded by the AUX1/LAX , PIN , and PILS (PIN-LIKES) genes, respectively ( Zhao et al, 2021 ). Members of the AUX1/LAX gene family are major auxin influx carriers, and mutations in its gene cause auxin-related developmental defects and are involved in the regulation of key plant processes, including root, and lateral root development, root gravitation and hair development, vascular patterns, seed germination, leaf morphogenesis, and embryo development ( Swarup and Bhosale, 2019 ).…”