Enolase2 regulates seed fatty acid accumulation via mediating carbon partitioning in Arabidopsis thaliana

Abstract

In many higher plants, fatty acid (FA) biosynthesis is coordinately regulated at multiple levels by intricate regulatory networks. However, the factors and their regulatory mechanisms underlying seed oil accumulation are still limited. Here, we identified that loss of glycolytic metalloenzyme enolase2 (AtENO2) activity increased the contents of total FAs and salicylic acid (SA) but reduced the accumulation of flavonoids and mucilage by regulating the expression of key genes involved in their biosynthesis pathway in Arabidopsis thaliana seeds. AtENO2 physically interacts with the transcription factor AtTGA5, which may participate in the regulation of SA levels.Non-targeted metabolomics analysis of eno2 À and WT also showed that the levels of three flavonoids, quercetin-3-galactoside, quercitrin, and epicatechin, were significantly decreased in eno2 À , and the flavonoid biosynthesis pathway was also enriched in the KEGG analysis. Meanwhile, the mutation of AtENO2 delayed silique ripening, thereby prolonging silique photosynthesis time, allowing siliques to generate more photosynthesis products for FA biosynthesis. These results reveal a molecular mechanism by AtENO2 to regulate seed oil accumulation in A. thaliana, providing potential targets for improving crop seed oil quality.

Busted: maternal modifiers of the triploid block involved in seed size control

“…However, the TTG1-FUSCA3 mechanism is only a minor increase in seed size. Enolase2 has also been reported to play a role in fatty acid accumulation during seed maturation by interacting with flavonoids and auxin ( 51 ). Other mechanisms, such as delayed endosperm cellularisation, increased carbohydrate accumulation, prolonged seed maturation or alterations in some other signalling pathways controlling seed size in maternal tissues, could be responsible for the increased seed size in ttg1axr1-3 double mutants.…”