Polar auxin transport (PAT) is facilitated by polar localization of PIN-FORMED (PIN) efflux carriers, which direct auxin flow and regulate developmental events. Brassinosteroids (BRs) and auxin work synergistically to promote growth, and in root geotropisms this cross-talk involves BR-directed polarization of PIN through the mobilization of F-actin. However, the role of BR in PAT during shoot growth, hair formation, and embryogenesis has not been well studied. Orchid seed are mature at a point in development that is analogous to the globular-stage of embryogenesis in typical angiosperms. Thus, this system provided a unique opportunity to study the effects of BR on PAT during embryogenesis-like events, including meristem/first leaf formation and protocorm/stem development, which is followed by protocorm hair formation. In this work, the degree to which BRs rescued embryo-like protocorms from the impact of PAT-disrupting agents, such as PAT inhibitors or high auxin levels, was determined based on growth responses. This study first established that auxin and BRs work together synergistically to promote seedling elongation in Spathoglottis. Repressed seedling growth caused by the PAT-disrupting agents was alleviated with eBL, suggesting that BRs enhance PAT in embryogenesis-like stages of young protocorms. However, similar responses were not evident in seed embryos. Results from this study also suggested that BRs may enhance orchid protocorm elongation by regulating auxin transport through an F-actin-mediated mechanism. With regard to protocorm hairs, increased eBL levels inhibited formation, whereas reduced BR biosynthesis altered hair patterning, and prevented outgrowth of auxin-stimulated hairs. Moreover, PAT inhibitors and repression of BR biosynthesis caused hair bud formation without hair outgrowth, suggesting a role for BR in PAT during protocorm hair development.
This research output has an Altmetric Attention Score of 2. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 23 September 2018.
All research outputs
#13,936,085
of 23,102,082 outputs
Outputs from Frontiers in Plant Science
#7,237
of 20,728 outputs
Outputs of similar age
#176,870
of 333,264 outputs
Outputs of similar age from Frontiers in Plant Science
#200
of 466 outputs
Altmetric has tracked 23,102,082 research outputs across all sources so far. This one is in the 38th percentile – i.e., 38% of other outputs scored the same or lower than it.
So far Altmetric has tracked 20,728 research outputs from this source. They receive a mean Attention Score of 3.9. This one has gotten more attention than average, scoring higher than 64% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 333,264 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 45th percentile – i.e., 45% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 466 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 56% of its contemporaries.
