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The role of auxin in developmentally regulated programmed cell death in lace plant
Author(s) -
Denbigh Georgia L.,
Dauphinee Adrian N.,
Fraser Meredith S.,
Lacroix Christian R.,
Gunawardena Arunika H. L. A. N.
Publication year - 2020
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/ajb2.1463
Subject(s) - auxin , biology , microbiology and biotechnology , programmed cell death , perforation , reactive oxygen species , botany , plant cell , vascular bundle , apoptosis , biochemistry , gene , materials science , metallurgy , punching
Premise Lace plant ( Aponogeton madagascariensis ) leaves are remodeled via developmental programmed cell death ( PCD ) to produce perforations located equidistantly between longitudinal and transverse veins. Auxin has been implicated in other developmental PCD processes in plants; however, the role of auxin in perforation formation in lace plant is unknown. Here the role of auxin in developmental PCD in lace plant was studied using two auxin inhibitors N ‐1‐naphthylphthalamic acid ( NPA ), an auxin transport inhibitor, and auxinole, a potent auxin antagonist. Methods Sterile cultures of lace plants were propagated and treated with NPA or auxinole. Leaf length, leaf width, and number of perforations were then analyzed. Vein patterning and perforation area were further examined in NPA ‐treated plants. Downstream PCD transduction events were investigated via spectrophotometric assays, histochemical staining, and immuno‐probing. Results Lace plants treated with NPA or auxinole produced leaves with fewer perforations compared to their respective controls. Although NPA treatment was insufficient to completely alter vein patterning, NPA ‐treated leaves did have significantly more atypical areoles compared to control leaves. Events involved in perforation formation in lace plant leaves were altered following treatment with NPA , including anthocyanin production, reactive oxygen species ( ROS ) accumulation, and the release of mitochondrial cytochrome c . Conclusions Our results indicated that inhibition of auxin signaling disrupts several downstream features of the lace plant PCD signaling cascade and results in fewer or no perforations. Therefore, we concluded that auxin signaling is important for developmentally regulated PCD in lace plant leaves.