Phytohormones play pivotal roles in the response of plants to various biotic and abiotic stresses. Boron (B) is an essential microelement for plants, and Brassica napus (B. napus) is hypersensitive to B deficiency. However, how auxin responds to B deficiency remained a dilemma for many years and little is known about how other phytohormones respond to B deficiency. The identification of B-efficient/inefficient B. napus indicates that breeding might overcome these constraints in the agriculture production. Here, we seek to identify phytohormone-related processes underlying B-deficiency tolerance in B. napus at the physiological and gene expression levels. Our study indicated low-B reduced indole-3-acetic acid (IAA) concentration in both the shoots and roots of B. napus, and affected the expression of the auxin biosynthesis gene BnNIT1 and the efflux gene BnPIN1 in a time-dependent manner. Low-B increased the jasmonates (JAs) and abscisic acid (ABA) concentrations and induced the expression of the ABA biosynthesis gene BnNCED3 and the ABA sensor gene BnPYL4 in the shoot. In two contrasting genotypes, the auxin concentration decreased more drastically in the B-inefficient genotype 'W10,' and together the expression of BnNIT1 and BnPIN1 also decreased more significantly in 'W10' under long-term B deficiency. While the JAs concentration was considerably higher in this genotype, and the ABA concentration was induced in 'W10' compared with the B-efficient genotype 'QY10.' Digital gene expression (DGE) profiling confirmed the differential expression of the phytohormone-related genes, indicating more other phyohormone differences involving in gene regulation between 'QY10' and 'W10' under low-B stress. Additionally, the activity of DR5:GFP was reduced in the root under low-B in Arabidopsis, and the application of exogenous IAA could partly restore the B-defective phenotype in 'W10.' Overall, our data suggested that low-B disturbed phytohormone homeostasis in B. napus, which originated from the change of transcriptional regulation of phytohormones-related genes, and the differences between genotypes may partly account for their difference in tolerance (B-efficiency) to low-B.
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 10 March 2016.
All research outputs
#14,711,526
of 22,852,911 outputs
Outputs from Frontiers in Plant Science
#9,064
of 20,198 outputs
Outputs of similar age
#164,738
of 297,860 outputs
Outputs of similar age from Frontiers in Plant Science
#184
of 481 outputs
Altmetric has tracked 22,852,911 research outputs across all sources so far. This one is in the 35th percentile – i.e., 35% of other outputs scored the same or lower than it.
So far Altmetric has tracked 20,198 research outputs from this source. They receive a mean Attention Score of 4.0. This one has gotten more attention than average, scoring higher than 54% 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 297,860 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 43rd percentile – i.e., 43% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 481 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 61% of its contemporaries.
