Tricoli, D. M. | Search bioRxiv

bioRxiv2024

Manipulation of the microRNA172 - AP2L2 interaction provides precise control of wheat and triticale plant height

The REDUCED HEIGHT (RHT) dwarfing alleles Rht-B1b and Rht-D1b were essential in the "Green Revolution" to optimize wheat plant height and increase grain yield. However, those alleles reduce coleoptile length limiting sowing depth, which triggered the search for alternative dwarfing genes. In this study, we engineered the interaction between miR172 and AP2L2 genes to fine-tune wheat and triticale plant height without affecting coleoptile and first-leaf length.

plant biology↗

bioRxiv2020

A chimera including a GROWTH-REGULATING FACTOR (GRF) and its cofactor GRF-INTERACTING FACTOR (GIF) increases transgenic plant regeneration efficiency

Genome editing allows precise DNA manipulation, but its potential is limited in many crops by low regeneration efficiencies and few transformable genotypes. Here, we show that expression of a chimeric protein including wheat GROWTH-REGULATING FACTOR 4 (GRF4) and its cofactor GRF-INTERACTING FACTOR 1 (GIF1) dramatically increases the efficiency and speed of regeneration in wheat, triticale and rice and expands the number of transformable wheat genotypes. Moreover, GRF4-GIF1 induces efficient wheat regeneration in the absence of exogenous cytokinins, which facilitates selection of transgenic plants without selectable markers. By combining GRF4-GIF1 and CRISPR-Cas9 technologies, we were able to generate large numbers of edited wheat plants. The GRF4-GIF1 transgenic plants were fertile and without obvious developmental defects, likely due to post-transcriptional regulatory mechanisms operating on GRF4 in adult tissues. Finally, we show that a dicot GRF-GIF chimera improves regeneration efficiency in citrus suggesting that this strategy can be expanded to dicot crops.

plant biology↗