ORCID Profile
0000-0001-8114-9891
Current Organisation
University of Adelaide
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Publisher: MDPI AG
Date: 31-05-2018
Publisher: Wiley
Date: 27-01-2023
DOI: 10.1111/NPH.18714
Abstract: In cereal species, grain size is influenced by growth of the ovule integuments (seed coat), the spikelet hull (lemma and palea) and the filial endosperm. Whether a highly conserved ovule tissue, the nucellus, has any impact on grain size has remained unclear. Immunolabelling revealed that the barley nucellus comprises two distinct cell types that differ in terms of cell wall homogalacturonan (HG) accumulation. Transcriptional profiling of the nucellus identified two pectin methylesterase (PME) genes, OVULE PECTIN MODIFIER 1 ( OPM1 ) and OPM2 , which are expressed in the unfertilized ovule but absent from the seed. Ovules from an opm1 opm2 mutant and plants expressing an ovule‐specific pectin methylesterase inhibitor (PMEI), exhibit reduced HG accumulation. This results in changes to ovule cell size and shape and ovules that are longer than wild‐type (WT) controls. At grain maturity, this is manifested as significantly longer grain. These findings indicate that cell wall composition during ovule development acts to limit ovule and seed growth. The investigation of ovule PME and PMEI activity reveals an unexpected role of maternal tissues in controlling grain growth before fertilization, one that has been lacking from models exploring improvements in grain size.
Publisher: Oxford University Press (OUP)
Date: 29-05-2018
DOI: 10.1104/PP.18.00342
Publisher: American Chemical Society (ACS)
Date: 02-01-2019
Publisher: Oxford University Press (OUP)
Date: 11-01-2016
DOI: 10.1104/PP.15.01690
Publisher: Wiley
Date: 03-2019
DOI: 10.1111/JIPB.12747
Abstract: Grain production in cereal crops depends on the stable formation of male and female gametes in the flower. In most angiosperms, the female gamete is produced from a germline located deep within the ovary, protected by several layers of maternal tissue, including the ovary wall, ovule integuments and nucellus. In the field, germline formation and floret fertility are major determinants of yield potential, contributing to traits such as seed number, weight and size. As such, stimuli affecting the timing and duration of reproductive phases, as well as the viability, size and number of cells within reproductive organs can significantly impact yield. One key stimulant is the phytohormone auxin, which influences growth and morphogenesis of female tissues during gynoecium development, gametophyte formation, and endosperm cellularization. In this review we consider the role of the auxin signaling pathway during ovule and seed development, first in the context of Arabidopsis and then in the cereals. We summarize the gene families involved and highlight distinct expression patterns that suggest a range of roles in reproductive cell specification and fate. This is discussed in terms of seed production and how targeted modification of different tissues might facilitate improvements.
Publisher: Springer Science and Business Media LLC
Date: 02-11-2015
DOI: 10.1038/NG.3435
Publisher: Public Library of Science (PLoS)
Date: 18-05-2017
Publisher: Oxford University Press (OUP)
Date: 20-05-2018
DOI: 10.1104/PP.17.01718
Publisher: Oxford University Press (OUP)
Date: 19-09-2019
DOI: 10.1093/JXB/ERZ407
Abstract: Overexpression of the HvCslF6 gene in hull-less barley grain perturbs sucrose uptake and allocation, and impairs transfer tissue and endosperm development
No related grants have been discovered for Neil Shirley.