Abstract
Auxin resistant 1/like aux1 (AUX/LAX), pin-formed (PIN) and ATP binding cassette subfamily B (ABCB/MDR/PGP) are three families of auxin transport genes. The development-related functions of the influx and efflux carriers have been well studied and characterized in model plants. However, there is scant information regarding the functions of auxin genes in Chinese cabbage and the responses of exogenous polar auxin transport inhibitors (PATIs). We conducted a whole-genome annotation and a bioinformatics analysis of BrAUX/LAX, BrPIN, and BrPGP genes in Chinese cabbage. By analyzing the expression patterns at several developmental stages in the formation of heading leaves, we found that most auxin-associate genes were expressed throughout the entire process of leafy head formation, suggesting that these genes played important roles in the development of heads. UPLC was used to detect the distinct and uneven distribution of auxin in various segments of the leafy head and in response to PATI treatment, indicated that the formation of the leafy head depends on polar auxin transport and the uneven distribution of auxin in leaves. This study provides new insight into auxin polar transporters and the possible roles of the BrLAX, BrPIN and BrPGP genes in leafy head formation in Chinese cabbage.
Highlights
A total of 52 sequences encoding putative genes were identified in Chinese cabbage, including 10 BrLAX, 15 BrPIN and 27 BrPGP genes, and they were named BrLAX1-10, BrPIN1-14 and BrPGP1-27 based on their chromosomal locations
To further identify the roles of the BrLAX, BrPIN and BrPGP genes in head formation in Chinese cabbage, the transcription of the three gene families was analyzed via quantitative real-time PCR using the 7th rosette leaf and the 25th head leaf at the heading stage (Fig. S2). These results showed that almost all of the evaluated genes were up-regulated during the rosette stage (Fig. 4A, Table S3), the stage at which we hypothesize that the auxin transport genes, BrLAXs, BrPINs and BrPGPs, began to affect the uneven auxin distribution in the rosette stage to generate the critical parameters of head formation
We detected the IAA contents of different segments of head and non-head leaves with PATI treatment (Fig. 6)
Summary
PAT has been demonstrated by auxin efflux inhibitors, such as 2,3,5-triiodobenzoic acid (TIBA) and 1-N-naphthylpthalamic acid (NPA)[29] These two PATIs were used to identify the candidate members of three gene families related to auxin transport. To understand the auxin response in Chinese cabbage, we used a genome-wide analysis to characterize three PAT-related gene families, LAX, PIN and PGP. UPLC was used to identify IAA content in HLs with and without PATI treatments, further demonstrating that head formation requires distinct auxin distribution patterns in different segments. These results provide a foundation for further studies on leafy head formation and PAT in Chinese cabbage. This work offers evidence for the regulation of leafy head formation by auxin genes and may assist with progress in the gene-engineered breeding of high-yield and high-quality crops
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
