boron and jasmonic-acid

The essential micronutrient boron (B) has key roles in cell wall integrity and B deficiency inhibits plant growth. The role of jasmonic acid (JA) in plant growth inhibition under B deficiency remains unclear. Here, we report that low B elevates JA biosynthesis in Arabidopsis thaliana by inducing the expression of JA biosynthesis genes. Treatment with JA inhibited plant growth and, a JA biosynthesis inhibitor enhanced plant growth, indicating that the JA induced by B deficiency affects plant growth. Furthermore, examination of the JA signaling mutants jasmonate resistant1, coronatine insensitive1-2, and myc2 showed that JA signaling negatively regulates plant growth under B deficiency. We identified a low-B responsive transcription factor, ERF018, and used yeast one-hybrid assays and transient activation assays in Nicotiana benthamiana leaf cells to demonstrate that ERF018 activates the expression of JA biosynthesis genes. ERF018 overexpression (OE) lines displayed stunted growth and up-regulation of JA biosynthesis genes under normal B conditions, compared to Col-0 and the difference between ERF018 OE lines and Col-0 diminished under low B. These results suggest that ERF018 enhances JA biosynthesis and thus negatively regulates plant growth. Taken together, our results highlight the importance of JA in the effect of low B on plant growth.

Topics: Arabidopsis; Arabidopsis Proteins; Boron; Cyclopentanes; Gene Expression Regulation, Plant; Oxylipins; Plants, Genetically Modified

Boron (B) is an essential micronutrient for plant growth and development. Jasmonic acid (JA) plays pivotal roles in plant growth, but the underlying molecular mechanism of JA involvement in B-deficiency-induced root growth inhibition is yet to be explored. In this study, we investigated the response of JA to B deficiency and the mechanism of JAR1-dependent JA signaling in root growth inhibition under B deficiency in Arabidopsis. B deficiency enhanced JA signaling in roots, and root growth inhibition was partially restored by JA biosynthesis inhibition. The jar1-1 (jasmonate-resistant 1, JAR1) mutant, and mutants of coronatine-insensitive 1 (coi1-2) and myc2 defective in JA signaling showed insensitivity to B deficiency. The ethylene-overproduction mutant eto1 and ethylene-insensitive mutant etr1 showed sensitivity and insensitivity to B deficiency, respectively, suggesting that ethylene is involved in the inhibition of primary root growth under B deficiency. Furthermore, after a decline in levels of EIN3, which may contribute to root growth, ethylene signaling was weakened in the jar1-1 mutant root under B deficiency. Under B deficiency, B concentrations were increased in the roots and shoots of the jar1-1 mutant, owing to the large root system and its activity. Therefore, our findings revealed that JA, which is involved in the inhibition of root growth under B deficiency, is regulated by JAR1-activated JA and ethylene signaling pathways.

Topics: Arabidopsis; Arabidopsis Proteins; Boron; Cyclopentanes; Gene Expression Regulation, Plant; Nucleotidyltransferases; Oxylipins; Plant Roots

Selenium (Se) is present in a wide variety of natural and man-made materials on Earth. Plants are able to tolerate and (hyper)accumulate Se to different extents. In fact, some species can tolerate and accumulate multiple elements. Puccinellia distans (P. distans), weeping alkali grass, is known to hyperaccumulate extreme concentrations of boron and tolerate high levels of salinity, therefore, we investigated the Se accumulation and tolerance capacities of this species. In addition, P. distans' Se tolerance mechanism was studied using a transcriptomic approach. The results of this study indicated that, when grown in a hydroponic system containing 80 or 120 μM Se, P. distans shoots accumulated from 1500 to 2500-fold more Se than plants grown without the element. Thus, P. distans was discovered to be a novel Se accumulator plant. RNA sequencing results and biochemical analyses helped to shed light on the Se tolerance and accumulation mechanism of P. distans. Here, we suggest that upregulation of Se assimilation and stress response genes may be due to induction of jasmonic acid signaling. In addition, we propose that the cell wall may play an important role in restriction of Se movement to the cytoplasm. Also, we hypothesize that Se accumulates in cells by sequestration of selenate in the vacuole.

Topics: Boron; Cyclopentanes; Drug Tolerance; Gene Expression Profiling; Hydroponics; Oxylipins; Poaceae; Selenic Acid; Selenium; Sequence Analysis, RNA