Recently, a research article entitled “ AGLF provides C-function in floral organ identity through transcriptional regulation of AGAMOUS in Medicago truncatula ” was published on the top journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). Assistant researcher Zhao Yang is the first author; professor Zhou Chuanen is the corresponding author. The key laboratory of plant development and environmental adaptation biology and School of Life Sciences are the first corresponding institutions.
Based on genetic studies in Arabidopsis thaliana and Antirrhinum majus, the ABC model has been theorized to explain the mechanism underlying floral organ development. In general, sepals are controlled by Class A genes; petals are controlled by Class A genes and Class B genes; stamens are controlled by Class B genes and Class C gene; and carpels are controlled by Class C gene only. Medicago truncatula has been studied as the model legume species, which develops different floral architecture from Arabidopsis. M. truncatula genome contains several canonical ABC genes but their mutants showed slightly different phenotypes. In this work, a novel gene, AGAMOUS-LIKE FLOWER (AGLF), was identified from a forward genetic screen of Medicago mutants. The mutant showed homeotic transformation of floral organs, with stamen and carpel replaced by multiple petals and sepals. AGLF was a single copy gene whose mutant display a similar phenotype as the well-studied Class C gene, AGAMOUS. This work represents a systematic research on floral organ development in Medicago truncatula and provides novel insight into breeding of other legume crops.
This work was supported by 973 Program Youth Project of the Ministry of Science and Technology of China, and the National Natural Science Foundation of China and of Shandong Province.