In:
PLOS Genetics, Public Library of Science (PLoS), Vol. 17, No. 8 ( 2021-8-5), p. e1009674-
Abstract:
In plants, the effective mobilization of seed nutrient reserves is crucial during germination and for seedling establishment. The Arabidopsis H + -PPase-loss-of-function fugu5 mutants exhibit a reduced number of cells in the cotyledons. This leads to enhanced post-mitotic cell expansion, also known as compensated cell enlargement (CCE). While decreased cell numbers have been ascribed to reduced gluconeogenesis from triacylglycerol, the molecular mechanisms underlying CCE remain ill-known. Given the role of indole 3-butyric acid (IBA) in cotyledon development, and because CCE in fugu5 is specifically and completely cancelled by ech2 , which shows defective IBA-to-indoleacetic acid (IAA) conversion, IBA has emerged as a potential regulator of CCE. Here, to further illuminate the regulatory role of IBA in CCE, we used a series of high-order mutants that harbored a specific defect in IBA-to-IAA conversion, IBA efflux, IAA signaling, or vacuolar type H + -ATPase (V-ATPase) activity and analyzed the genetic interaction with fugu5–1 . We found that while CCE in fugu5 was promoted by IBA, defects in IBA-to-IAA conversion, IAA response, or the V-ATPase activity alone cancelled CCE. Consistently, endogenous IAA in fugu5 reached a level 2.2-fold higher than the WT in 1-week-old seedlings. Finally, the above findings were validated in icl–2 , mls–2 , pck1–2 and ibr10 mutants, in which CCE was triggered by low sugar contents. This provides a scenario in which following seed germination, the low-sugar-state triggers IAA synthesis, leading to CCE through the activation of the V-ATPase. These findings illustrate how fine-tuning cell and organ size regulation depend on interplays between metabolism and IAA levels in plants.
Type of Medium:
Online Resource
ISSN:
1553-7404
DOI:
10.1371/journal.pgen.1009674
DOI:
10.1371/journal.pgen.1009674.g001
DOI:
10.1371/journal.pgen.1009674.g002
DOI:
10.1371/journal.pgen.1009674.g003
DOI:
10.1371/journal.pgen.1009674.g004
DOI:
10.1371/journal.pgen.1009674.g005
DOI:
10.1371/journal.pgen.1009674.g006
DOI:
10.1371/journal.pgen.1009674.g007
DOI:
10.1371/journal.pgen.1009674.g008
DOI:
10.1371/journal.pgen.1009674.s001
DOI:
10.1371/journal.pgen.1009674.s002
DOI:
10.1371/journal.pgen.1009674.s003
DOI:
10.1371/journal.pgen.1009674.s004
DOI:
10.1371/journal.pgen.1009674.s005
DOI:
10.1371/journal.pgen.1009674.s006
DOI:
10.1371/journal.pgen.1009674.s007
DOI:
10.1371/journal.pgen.1009674.s008
DOI:
10.1371/journal.pgen.1009674.s009
DOI:
10.1371/journal.pgen.1009674.s010
DOI:
10.1371/journal.pgen.1009674.s011
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2021
detail.hit.zdb_id:
2186725-2
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