Structural and physiological characterization during wheat pericarp development

et al. 2014

J. Sci. Food Agric.

Section: Resultsmentioning

confidence: 99%

Comparison of starch granule development and physicochemical properties of starches in wheat pericarp and endosperm

Zhou

et al. 2014

J. Sci. Food Agric.

“…The contribution of ear photosynthesis to grain filling in wheat and barley was estimated to be between 10% and 76%, and, of this, 33– 43% has been attributed to pericarp photosynthesis (Caley et al 1990). In wheat, photosynthetic activity peaked at about 15–20 DAF, coinciding with maximum Chl content in the pericarp green layer (Caley et al 1990, Xiong et al 2013). In rice, pericarp photosynthesis was reported in the grains of transgenic rice plants with the C4- Pdk gene of maize (Fukayama et al 2001).…”

Section: Discussionmentioning

confidence: 99%

Complementary Proteome and Transcriptome Profiling in Developing Grains of a Notched-Belly Rice Mutant Reveals Key Pathways Involved in Chalkiness Formation

Wang

Plant and Cell Physiology

et al. 2017

Rice grain chalkiness is a highly complex trait involved in multiple metabolic pathways and controlled by polygenes and growth conditions. To uncover novel aspects of chalkiness formation, we performed an integrated profiling of gene activity in the developing grains of a notched-belly rice mutant. Using exhaustive tandem mass spectrometry-based shotgun proteomics and whole-genome RNA sequencing to generate a nearly complete catalog of expressed mRNAs and proteins, we reliably identified 38,476 transcripts and 3,840 proteins. Comparison between the translucent part and chalky part of the notched-belly grains resulted in only a few differently express genes (240) and differently express proteins (363), thus making it possible to focus on ‘core’ genes or common pathways. Several novel key pathways were identified as of relevance to chalkiness formation, in particular the shift of C and N metabolism, the down-regulation of ribosomal proteins and the resulting low abundance of storage proteins especially the 13 kDa prolamin subunit, and the suppressed photosynthetic capacity in the pericarp of the chalky part. Further, genes and proteins as transporters for carbohydrates, amino acid/peptides, proteins, lipids and inorganic ions showed an increasing expression pattern in the chalky part of the notched-belly grains. Similarly, transcripts and proteins of receptors for auxin, ABA, ethylene and brassinosteroid were also up-regulated. In summary, this joint analysis of transcript and protein profiles provides a comprehensive reference map of gene activity regarding the physiological state in the chalky endosperm.

“…1e), showing that starch mainly accumulated in the endosperm, while pericarp was stained decreasingly with I 2 /KI, indicating gradual disappearance of the starch accumulated in pericarp (Xiong et al 2013a). During 0-12 DAA, the crease region including vascular bundle, chalaza, and nucellar projection were increasingly stained with 2,3,5-triphenyl-2H-tetrazolium chloride, indicating that dehydrogenase activity increased after anthesis and attained a maximum at 12 DAA (Fig.…”

Section: Resultsmentioning

confidence: 93%

Structural development of wheat nutrient transfer tissues and their relationships with filial tissues development

et al. 2014

Nutrients from spikelet phloem are commonly delivered to endosperm via caryopsis nutrient transfer tissues (NTTs). Elucidation of NTTs development is paramount to developing an understanding of the control of assimilate partitioning. Little information was available on the structural development of the entire NTTs and their functions, particularly those involved in the relationship between development of NTTs and growth of filial tissues including endosperm and embryo. In this study, wheat caryopses at different development stages were collected for observation of the NTTs by light microscopy, stereoscopic microscopy, and scanning electron microscopy. The cytological features of NTTs in the developing wheat caryopsis were clearly elucidated. The results were as follows: NTTs in the wheat caryopsis include maternal transfer tissues that are composed of vascular bundle, chalaza and nucellar projection transfer cells, and endosperm transfer tissues that consist of the aleurone transfer cells, starchy endosperm transfer cells, and endosperm conducting cells. The initiation, development, and apoptosis of these NTTs revealed the pattern of temporal and spatial gradient and were closely coordinated with endosperm and embryo development. These results may give us a further understanding about the functions of NTTs and their relationships with endosperm and embryo development.