Department of Plant Biology, College of Biological Sciences, University of California, Davis, Davis, United States; The Genome Center, College of Biological Sciences, University of California, Davis, Davis, United States
Alexander Nedo
Delaware Biotechnology Institute, University of Delaware, Newark, United States; Department of Biological Sciences, College of Arts and Sciences, University of Delaware, Newark, United States
Ali Alqarni
Delaware Biotechnology Institute, University of Delaware, Newark, United States; Department of Biological Sciences, College of Arts and Sciences, University of Delaware, Newark, United States; Department of Plant and Soil Sciences, College of Agriculture and Natural Resources, University of Delaware, Newark, United States
Li Ren
Department of Plant and Soil Sciences, College of Agriculture and Natural Resources, University of Delaware, Newark, United States
Kyle Hoban
Delaware Biotechnology Institute, University of Delaware, Newark, United States; Department of Biological Sciences, College of Arts and Sciences, University of Delaware, Newark, United States
Shannon Modla
Delaware Biotechnology Institute, University of Delaware, Newark, United States
John H McDonald
Department of Biological Sciences, College of Arts and Sciences, University of Delaware, Newark, United States
Chandra Kambhamettu
Department of Plant and Soil Sciences, College of Agriculture and Natural Resources, University of Delaware, Newark, United States; Department of Computer and Information Sciences, College of Engineering, University of Delaware, Newark, United States
Department of Plant Biology, College of Biological Sciences, University of California, Davis, Davis, United States; The Genome Center, College of Biological Sciences, University of California, Davis, Davis, United States
Delaware Biotechnology Institute, University of Delaware, Newark, United States; Department of Biological Sciences, College of Arts and Sciences, University of Delaware, Newark, United States; Department of Plant and Soil Sciences, College of Agriculture and Natural Resources, University of Delaware, Newark, United States
Dynamic tubular extensions from chloroplasts called stromules have recently been shown to connect with nuclei and function during innate immunity. We demonstrate that stromules extend along microtubules (MTs) and MT organization directly affects stromule dynamics since stabilization of MTs chemically or genetically increases stromule numbers and length. Although actin filaments (AFs) are not required for stromule extension, they provide anchor points for stromules. Interestingly, there is a strong correlation between the direction of stromules from chloroplasts and the direction of chloroplast movement. Stromule-directed chloroplast movement was observed in steady-state conditions without immune induction, suggesting it is a general function of stromules in epidermal cells. Our results show that MTs and AFs may facilitate perinuclear clustering of chloroplasts during an innate immune response. We propose a model in which stromules extend along MTs and connect to AF anchor points surrounding nuclei, facilitating stromule-directed movement of chloroplasts to nuclei during innate immunity.
