Strigolactones interact with other plant hormones in many situations

Strigolactones are interesting phytohormones in their own right, but Luke Omoarelojie and colleagues say we should be looking at cross-talk with other hormones too.

If you work on plant growth, you’re probably familiar with Strigolactones (SLs). One reason is that researchers are finding that SLs seem to have a role in many parts of the plant. In a review in Annals of Botany, Omoarelojie and colleagues look at Strigolactones and, in particular, their cross-talk with other phytohormones. The authors say that recent discoveries on the actions of SLs do not diminish the importance of other hormones. On the contrary, the scientists say that cross-talk with other hormones is why research into SLs matters. “The pivotal role of ABA, jasmonates and SA hormonal actions in enabling plants cope with limiting and stressful ambient conditions cannot be overemphasized. In addition, with the emerging roles of SLs in this aspect of plant development, it is imperative to characterize the crosstalk between SLs and these hormones to develop a model of the circuit of hormonal actions that drive plants’ innate response and defence mechanisms against biotic and abiotic stress in their environment.”

Roles of strigolactones

The team outline many roles for strigolactones. Recently we covered the germination of parasitic plants, which could be an offshoot of plants using strigolactones to encourage fungal partners to approach. 

However, it’s not just a role in the roots, strigolactones also contribute to the development of shoots, regulating photomorphogenesis and shoot branching. They also help plants survive stresses, such as nutrient deficiencies or drought.

In their review, Omoarelojie and colleagues identify plenty of opportunities for strigolactones to interact with other hormones, including auxin, cytokinin, abscisic acid (ABA), gibberellins, ethylene and others.

The authors identify SLs as a major research topic for the coming years. “The impact of epigenetic cues and associated regulatory mechanisms on the interactions between SL signals and those of other phytohormones as well as their evolution during plant adaptation to new environments require much research attention. These are crucial if SL-mediated plant responses are to be fully understood in the face of dynamic ambient conditions, as is being experienced with the current change in global weather and climate patterns and the rapidly evolving microbial communities within the rhizosphere.”