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The shoot apical meristem (SAM) of higher plants comprises distinct functional zones. The central zone (CZ) is located at the meristem summit and harbors pluripotent stem cells. Stem cells undergo cell division within the CZ and give rise to descendants, which enter the peripheral zone (PZ) and become recruited into lateral organs. Stem cell daughters that are pushed underneath the CZ form rib meristem (RM). To unravel the mechanism of meristem development, it is essential to know how stem cells adopt distinct cell fates in the SAM. Here, we show that meristem patterning and floral organ primordia formation, besides auxin transport, are regulated by auxin biosynthesis mediated by two closely related genes of the TRYPTOPHAN AMINOTRANSFERASE family. In Arabidopsis SAM, TAA1 and TAR2 played a role in maintaining auxin responses and the identity of PZ cell types. In the absence of auxin biosynthesis and transport, the expression pattern of the marker genes linked to the patterning of the SAM is perturbed. Our results prove that local auxin biosynthesis, in concert with transport, controls the patterning of the SAM into the CZ, PZ and RM.
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http://dx.doi.org/10.1242/dev.202014 | DOI Listing |
Physiol Plant
September 2025
Plant BioSystems, Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Auxins are involved in the regulation of fruit set and development; however, the role of IAA is unclear in pea (Pisum sativum) since the endogenous auxin 4-Cl-IAA appears to be the auxin stimulating ovary (pericarp) growth. To further understand the role of auxins during fruit development, auxin localization, quantitation, transport, and gene expression activity were assessed in this model legume species. IAA levels and auxin activity (DR5::β-Glucuronidase [GUS] staining and enzyme activity) were substantially reduced in the pericarp vascular tissues, pedicels, and peduncles of fruit upon seed removal, reflecting auxin transport streams derived from the seeds through these tissues.
View Article and Find Full Text PDFArch Microbiol
September 2025
School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
Endophytic fungi are nonpathogenic fungi that live symbiotically in the interior of healthy plant tissues and form mutualistic associations with their hosts. These fungi are critically involved in promoting plant development, strengthening plant uptake of nutrients, and improving plant resistance to biotic and abiotic stress conditions. Endophytic fungi improve plant growth by synthesizing phytohormones (e.
View Article and Find Full Text PDFmSphere
September 2025
Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, USA.
Apicomplexan AP2 (ApiAP2) family proteins are a family of transcription factors that are known to regulate gene expression in apicomplexan pathogens, including . In this study, we focused on TgAP2X-7, a member of the APiAP2 family that is predicted to be essential for fitness. Endogenous tagging of TgAP2X-7 followed by immunofluorescence analysis revealed that it's a cell cycle-regulated nuclear protein with peak expression in the G1 phase.
View Article and Find Full Text PDFFront Plant Sci
August 2025
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Non-Timber Forestry, Chinese Academy of Forestry, Zhengzhou, China.
Introduction: Shikimic acid, as a critical precursor for oseltamivir synthesis in antiviral pharmaceuticals, faces escalating global demand. Although leaves have emerged as a promising natural source of shikimic acid owing to their exceptional content of this valuable compound and substantial biomass production capacity, the molecular mechanisms underlying its biosynthesis and downstream metabolic regulation in leaves remain largely unknown.
Methods: Here, the concentration of shikimic acid in 33 clones were assessed, and 1# (referred as HS) had the highest level.
Physiol Plant
September 2025
Agriculture and Agri-Food Canada, Saskatoon Research and Development Centre, Saskatoon, Saskatchewan, Canada.
Dormancy release and germination of the seed are two separate, but continuous phases controlled by both external (e.g., light and temperature) and internal (e.
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