Abstract
Elucidating the genetic mechanisms associated with the transition from the vegetative to reproductive phase in the rubber tree has great importance for both theoretical guidance and practical application to yield genetic improvement. At present, many transcription factors, including those that belong to the MADS-box gene family, have been revealed to have roles in regulating the transition from vegetative growth to reproductive growth. However, to the best of our knowledge, the Mad-box gene family from H. brasiliensis Müll. Arg. has not been characterized in detail. To investigate members of the HbMADS-box gene family associated with floral organ and inflorescence development in H. brasiliensis, we performed genome-wide identification and analysis of the MADS-box gene family related to flower development in H. brasiliensis, and a total of 20 MADS-box genes were newly identified in the H. brasiliensis genome. Expression profiling revealed that HbMad-box genes were differentially expressed in various tissues, which indicated that HbMad-box genes may exert different functions throughout the life cycle. Additionally, 12 genes (HbSEP, HbAGL9.1, HbAGL9.2, HbCMB1, HbCMB1-L, HbAGL6, HbAGL8, HbAP1, HbAG, HbDEFL, HbTT16, and HbPADS2) were found to be associated with the differentiation of flower buds and may be involved in flower development in H. brasiliensis. All of these floral-enriched HbMADS-box genes were regulated by hormone, salt, cold, high-temperature, and drought stresses. The present study is the first to carry out the genome-wide identification and analysis of the MADS-box gene family related to flower development in H. brasiliensis, and 20 new HbMad-box genes were identified in H. brasiliensis. Most of the newly identified HbMad-box genes were found to be associated with the differentiation of flower buds and may be involved in flower development in H. brasiliensis. Our results demonstrated that HbMad-box genes may be multifunctional regulators that have roles in distinct aspects of development, and are mainly involved in the maintenance of floral organ and inflorescence development.
Highlights
Natural rubber (NR) is an important industrial and strategic raw material, and has been applied to many aspects of social production [1]
Our results show that different HbMADS-box genes responded differently to abiotic stress, which indicates that stress responses of H. brasiliensis are regulated by many factors, involving a variety of signaling pathways
Our results revealed that HbSEP, HbAGL9.1, HbAGL9.2, HbCMB1, HbCMB1-L, HbAGL6, HbAGL8, HbAP1, HbAG, HbDEFL, and HbPADS2 may mainly regulate the differentiation of flower buds and could help regulate reproduction in H. brasiliensis; whereas HbTT16 may mainly regulate the development of fruits and female organs in the rubber tree
Summary
Natural rubber (NR) is an important industrial and strategic raw material, and has been applied to many aspects of social production [1]. Arg.) is the only commercial source of NR because of its high yield and the excellent physical properties of its rubber products [2], and it supplied 92% of the 10.2 million tons of NR consumed worldwide in 2016 [3]. To meet the growing demand for NR, it is necessary to expand the planting area of rubber trees. The rubber tree originates from the Amazon rainforest, so the planting area must be located in sub-tropical to tropical zones [4]. There is an urgent need to improve the rubber yield per area
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
