Physiological function of strigolactones in host plants : recent advances(<Feature Articles>Strigolactone)

Abstract

Strigolactones (SLs) are released from plant roots to soil and function as communication signals for symbiosis and parasitism in the rhizoshere. In addition, SLs are a new class of hormones that inhibit shoot branching of the host plants. It is an interesting question why SLs play an important role in both communication with other organisms and inhibition of shoot branching. Auxin and cytokinin are also essential hormones to regulate shoot branching. It is important to understand how auxin, cytokinin, and SLs interact each other. Although two carotenoid cleavage dioxygenases (CCDs) and a cytochrome P450 monooxygenase contribute to SL biosynthesis and an F-box protein is involved in the perception or signal transduction in the SL pathway, more genes are likely to be required to produce SLs and transmit the signals. Furthermore, SLs may have other function in host plants in addition to the inhibition of shoot branching. Many researchers address these questions and contribute to new findings. Here, I introduce recent advances on the physiological function of SLs in the host plants.