Seed-Specifically Overexpressed Arabidopsis Cytochrome P450 85A2 Promotes Vegetative and Reproductive Growth and Development of Arabidopsis thaliana

Arabidopsis Cytochrome P450 85A2 (AtCYP85A2) was introduced to Arabidopsis thaliana seeds using a seed-specific promoter, pAt5g54000. GUS (beta-Glucuronidase) activity and RT-PCR analysis demonstrated that AtCYP85A2 overexpression only occurred in seeds of a transgenic plant, pAt5g54000-AtCYP85A2::Col-0. A crude enzyme solution prepared pAt5g54000-AtCYP85A2::Col-0 seeds successfully catalyzed the conversion of castasterone (CS) to brassinolide (BL), which was not detected in wild-type seeds. Furthermore, a higher level of CS and BL was detected in pAt5g54000-AtCYP85A2::Col-0 seeds compared to untransformed seeds, thus demonstrating that seed-specific overexpression of AtCYP85A2 efficiently encoded a bi-functional enzyme for brassinosteroids 6-oxidase/brassinolide synthase to generate CS and BL in seeds of pAt5g54000-AtCYP85A2::Col-0. Compared to the wild type, pAt5g54000-AtCYP85A2::Col-0 produced substantially larger seeds with a high concentration of nutrients due to an enhancement in brassinosteroids signaling. Additionally, pAt5g54000-AtCYP85A2::Col-0 exhibited superior seed germination, seedling and rosette plant growth, and flower and silique formation, indicating that seed-specific AtCYP85A2 expression activates overall vegetative and reproductive growth and development in A. thaliana.

Automated summary

Introducing the Arabidopsis Cytochrome P450 85A2 gene into Arabidopsis seeds can significantly enhance plant growth and development, leading to increased seed yields and improved plant traits.