Novel candidate genes for inducing parthenogenesis in Arabidopsis and soybean

Background

Apomixis, or asexual clonal reproduction through seeds, is widely regarded as a revolutionary tool for the future of crop improvement. Indeed, apomixis allows for the one-step fixation of any important trait across multiple generations and the full exploitation of heterosis, simplifying hybrid and cultivar production.

One of the key steps of this reproductive system is the formation of autonomous embryos from the egg cell without fertilization (parthenogenesis). This process occurs naturally in apomictic plants, through heterochronic expression of embryo-identity-promoting transcription factors like PARTHENOGENESIS/DAZ3 and BABY BOOM. Parthenogenesis can also be induced in sexually reproducing plants through ectopic expression of these transcription factors in the egg cell. To date, engineering parthenogenesis at reasonably high rates has been achieved in monocots, whereas its induction in dicots has been less successful.

Aim of the Project

Using a forward genetics approach, we aim to evaluate new candidate transcription factors and other DNA-binding proteins for their ability to induce parthenogenesis. We identified a large set of candidate parthenogenesis genes by comparing expression data from Arabidopsis zygotes with expression data from purified 2–4-celled embryogenic structures from in vitro microspore embryo cultures. These genes will be evaluated for their ability to induce parthenogenesis in the model plant Arabidopsis thaliana, and the functions and expression patterns of interesting candidate genes will be further characterized.

Soybean is a major food and feed crop. However, its self-pollinating reproductive system has prevented the development of efficient commercial crossing systems to produce F1 hybrids and exploit hybrid vigor. Therefore, we will use soybean as a proof of concept to verify the possibility of introducing the parthenogenesis trait into a strictly self-pollinating dicot crop.