Genome-wide identification and expression analysis of CaLAX and CaPIN gene families in pepper (Capsicum annuum L.) under various abiotic stresses and hormones treatments

Auxin plays key roles in regulating plant growth and development as well as in responses to environmental stresses. The intercellular transport of auxin is mediated by four gene families, with the ATP-binding cassette family B (ABCB), the Auxin resistant1/ like (AUX1AUX/LAX) family, the pin-formed（PIN）families, and the PIN-LIKES (PILS) family. Here, the latest assembled pepper genome was used to characterise and analyse the CaLAX and CaPIN families. Genome-wide investigations into these families, including chromosomal distributions, phytogenic relationships and intron/exon structures, were performed. In total, 4 CaLAXs and 10 CaPINs were mapped to 10 chromosomes. Most of these genes exhibited varied tissue-specific expression patterns assessed by quantitative real-time PCR. The expression profiles of the CaLAX and CaPIN genes under various abiotic stresses (salt, drought, and cold), exogenous phytohormones (IAA, 6-BA, ABA, SA and MeJA) and polar auxin transport inhibitors treatments were evaluated. Most C...