Euryale Small Auxin Up RNA62 promotes cell elongation and seed size by altering the distribution of indole-3-acetic acid under the light

Abstract

Euryale (Euryale ferox Salisb.) is an aquatic crop used as both food and drug in Asia, but its utilization is seriously limited due to low yield. Previously, we hypothesized that Euryale small auxin up RNAs (EuSAURs) regulate seed size, but the underlying biological functions and molecular mechanisms remain unclear. Here, we observed that the hybrid Euryale lines (HL) generate larger seeds with higher indole-3-acetic acid (IAA) concentrations than those in the North Gordon Euryale (WT). Histological analysis suggested that a larger ovary in HL is attributed to longer cells around. Overexpression of EuSAUR62 in rice (Oryza sativa L.) resulted in larger glumes and grains and increased the length of glume cells. Immunofluorescence and protein interaction assays revealed that EuSAUR62 modulates IAA accumulation around the rice ovary by interacting with the rice PIN-FORMED 9, an auxin efflux carrier protein. Euryale basic region/leucine zipper 55 (EubZIP55), which was highly expressed in HL, directly binds to the EuSAUR62 promoter and activated the expression of EuSAUR62. Constant light increased the expression of both EubZIP55 and EuSAUR62 with auxin-mediated hook curvature in HL seedlings. Overall, we proposed that EuSAUR62 is a molecular bridge between light and IAA and plays a crucial role in regulating the size of the Euryale seed.

Comparative Anatomical and Transcriptomics Reveal the Larger Cell Size as a Major Contributor to Larger Fruit Size in Apricot

“…This finding is inconsistent with our results, which show that the expressions of five AUX/IAAs (PaF106G0100000592.0, PaF106G0300013748.01, PaF106G0300013749.01, PaF106G0800029753.01, and PaF106G0800029755.01) are significantly upregulated during the second cell expansion process (stages AF7 and AF8) in our larger-fruit 'Sungold' compared to small-fruit 'F43' (Figure 4b). The research on EuSAUR62 promoting cell elongation and thereby seed size is elucidated in Euryale [67], which supports our point that SUARs are positively related to the cell expansion during the CEP of 'Sungold', such as PaF106G0400016604.01, PaF106G0600022656.01, PaF106G0700026812.01, PaF106G0800030700.01, and PaF106G0800031621.01 (Figure 4b). In contrast, we also recognized that one AUX/IAA (PaF106G0300013934.01) and two SAURs (PaF106G0200008604.01 and PaF106G0200009291.01) were significantly downregulated during the CEP of 'Sungold', which could be candidate genes that promote the cell expansion after being suppressed in larger fruit.…”

Discovering novel genomic regions explaining adaptation of bread wheat to conservation agriculture through GWAS

“…SNP AX94650173 (21.89% PVE) on Chr2A was found to be linked to gene TraesCS2A02G212200 translating for “ Transcription factor UDT1 ” and SNP AX94707304 (26.90% PVE) on Chr6B was linked with two genes TraesCS6B02G360300 and TraesCS6B02G360500 which code for proteins “ Chloroplastic Soluble inorganic pyrophosphatase 6 ” and “ WAT1-related protein At2g39510 ”. The WALLS ARE THIN 1 (WAT1) gene has been reported to play a key role in cell elongation through auxin transport, which signifies its effect on spike length modification 120 . Interestingly, many QTLs for spike length have been reported to be present in the 2AS region where SNP AX94650173 was found to be associated with SL in our present study 121 .…”