"Intracellular communication of abiotic stress, memory and recovery: from model systems to crops"

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Thursday 12 April 2018, 11:00 - 12:30

 
ABSTRACT

Abiotic stress such as excess-light and drought cause significant crop losses by reducing photosynthetic efficiency and preventing yield potentials to be realized1. Conversely, slow recovery from, or constitutive acclimation to, stress can impair growth and yield3. Multiple components of excess-light and drought stress induction pathways have been identified. However, we have very little understanding of the reverse processes that are required to signal recovery and for resetting the transcriptome. We are employing large scale and systems approaches to investigate the processes and mechanisms enabling both stress tolerance and recovery from stress, including transcriptome, degradome and methylome profiling4,5.

Management of oxidative stress in plant chloroplasts involves signaling pathways to the nucleus that trigger stress response mechanisms, a process known as retrograde signalling1. Yet, how oxidative stress is initially sensed in the chloroplast to activate accumulation of a stress signal remained enigmatic1. We have shown that inactivation of a phosphatase, SAL1, by oxidative stress in chloroplasts controls accumulation of its substrate, PAP (3?-phosphoadenosine 5?- phosphate) which acts as a chloroplast stress retrograde signal2. We have also shown that the SAL1- retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis6. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses with applications to drought tolerance in crops.

 

1 Chan et al (2016) Ann Rev Plant Biology 67:25-53

2 Chan et al. (2016) PNAS 113: E4567-E4576

3 Crisp et al 2016) Science Advances 2: e1501340

4 Crisp et al (2017) Plant Cell 290: 1836-63

5 Ganguly et al (2017) Plant Physiology 175: 1893-1912

6 Pornsiriwong*, Estavillo*, Chan* et al (2017) eLIFE 6: e23361

 

 

 

 

Location Jozef Schell Seminar Room
Contact Prof Barry Pogson
ARC Centre of Excellence in Plant Energy Biology
Australian National University
AUSTRALIA