Light regulation of plant immunity. Keynote Lecture

BALLARE CL

Córdoba

Conferencia; 16th International Congress of Photobiology. Intl. Union Photobiology; 2014

Light regulation of plant immunity Carlos L. Ballaré IFEVA, CONICET?Universidad de Buenos Aires, C1417DSE Buenos Aires and IIB-INTECH, CONICET?Universidad Nacional de San Martín, B1650HMP Buenos Aires, Argentina; E-mail: ballare@ifeva.edu.ar Plant immunity against pathogens and herbivores is a central determinant of plant fitness in natural plant communities and crop yield in agroecosystems. Plant immune responses are orchestrated by two key hormones: jasmonic acid (JA) and salicylic acid (SA). Recent work has demonstrated that in plants of shade-intolerant species, which include the majority of those grown as grain crops, light is a major modulator of immune responses. Light signals that indicate proximity of competitors, such as a low red to far-red (R:FR) ratio, down-regulate the expression of JA- and SA-induced immune responses against pests and pathogens [1]. This down-regulation, which is caused by inactivation of the photoreceptor phytochrome B (phyB), is likely to help the plant to efficiently redirect resources to rapid growth when the competition threat posed by other plants is high [2]. In this lecture, I will address the molecular mechanisms that link phyB with JA signaling and defense activation. A better understanding of the map of molecular connections between photoreceptors and the hormonal regulators of plant immunity will provide a functional framework to understand the mechanisms used by plants to deal with fundamental resource allocation trade-offs under dynamic conditions of biotic stress. This mechanistic understanding is likely to provide important clues to breeding programs aimed to increase crop plant resistance to pests and pathogens [3]. Acknowledgments Work in our lab is supported by CONICET and ANPCyT. [1] C. L. Ballaré, Annu. Rev. Plant Biol. 2014, 65, 335. [2] J. E. Moreno, Y. Tao, J. Chory and C. L. Ballaré, Proc. Natl. Acad. Sci. USA 2009, 106, 4935. [3] C. L. Ballaré, C. A. Mazza, A. T. Austin and R. Pierik, Plant Physiol. 2012, 160, 145.