Genome Expression during Normal Leaf Development

Dean, Caroline; Leech, Rachel M.

doi:10.1104/pp.70.6.1605

Cited by 53 publications

(18 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in the range postulated (Molz and Boyer 1978) and reported (Boyer et al 1985) for growing hypocotyl tissue of soybean (however, see Malone and Tomos 1992). Provided that xylem Y was uniform along the zone (the vessel elements might have still been alive and contained end walls, Dean and Leech 1982), then the present results indicate that the resistance to water movement between xylem and expanding epidermal cell changed along the growth zone and limited growth most in Hoagland-plants ± maybe due to anatomical changes (number or length of epidermal, mesophyll and vessel-element cells; Dean and Leech 1982).…”

Section: What Reduces Ler In N-limited Barley Plants?mentioning

confidence: 83%

Why do leaves and leaf cells of N-limited barley elongate at reduced rates?

Fricke

McDonald

Mattson-Djos

1997

Planta

View full text Add to dashboard Cite

The objective of the present study was to assess whether, in barley, nitrogen supply limits the rate of leaf elongation through a reduction in (relative) cell elongation rate and whether this is attributable to a reduced turgor, a reduced availability of osmolytes or, by implication, changed wall properties. Plants were grown on full-strength Hoagland solution (``Hoagland''-plants), or on N-de®cient Hoagland solution while receiving N at a relative addition rate of 16 or 8% N á plant-N A1 á d A1 (``16%-'' and``8%-plants''). Hoagland-plants were demand-limited, whereas 16%-and 8%-plants were supply-limited in N. Third leaves were analysed for leaf elongation rate and ®nal epidermal cell length, and, within the basal growing region, for the spatial distribution of relative segmental elongation rates (RSER, pin-pricking method), epidermal cell turgor (cell-pressure probe), osmotic pressure (OP, picolitre osmometry) and water potential (Y). During the development of the third leaf, plants grew at relative growth rates (relative increase in fresh weight ) of 18.2, 15.6 and 8.1% á d A1 (Hoagland-, 16%-and 8%-plants, respectively). Final leaf length and leaf elongation rate were highest in Hoagland plants (ca. 34.1 cm and 2.33± 2.60 mm á h A1 , respectively), intermediate in 16%-plants (31.0 cm and 1.89±1.96 mm á h A1 ) and lowest in 8%-plants (29.4 cm and 1.41±1.58 mm á h A1 ). These dierences were accompanied by only small dierences in ®nal cell length, but large dierences in cell-¯ux rates (146, 187 and 201 cells á cell-®le A1 á d A1 in 8%-, 16%-and Hoagland-plants, respectively). The length of the growth zone (32±38 mm) was not much aected by Nlevels (and nutrient technique). A decrease in RSER in the growth zone distal to 10 mm produced the signi®-cant eect of N-levels on leaf elongation rate. In all treatments, cell turgor was almost constant throughout the growing region, as were cell OP and Y in 16%-and 8%-plants. In Hoagland-plants, however, cell OP increased by ca. 0.1 MPa within the zone of highest elongation rates and, as a consequence, cell Y decreased simultaneously by 0.1 MPa. Cell Y increased considerably where elongation ceased. Within the zone where dierences in RSERs were highest between treatments (10±34 mm from base) average turgor was lowest, OP highest and Y most negative in Hoagland-compared to 8%-and 16%-plants (P < 0.001), but not signi®cantly dierent between 8%-and 16%-plants.Abbreviations and symbols: LER = leaf elongation rate; OP = osmotic pressure; Y = water potential; RAR = relative addition rate; RIFW = relative increase in fresh weight; RSER = relative segmental elongation rate

show abstract

Section: What Reduces Ler In N-limited Barley Plants?mentioning

confidence: 83%

Why do leaves and leaf cells of N-limited barley elongate at reduced rates?

Fricke

McDonald

Mattson-Djos

1997

Planta

View full text Add to dashboard Cite

show abstract

“…10 7 Rubisco subunits [15], 106 Photosystem I, Photosystem II, ATP synthase and Cytochrome b6/f complexes [41], 10 4 to 10 5 ribosomes [28] to less t h a n 10 4 RNA polymerase complexes (unpublished data from this lab) per chloroplast. In general, the abundance of chloroplast-encoded proteins is correlated with their corresponding mRNA levels [49].…”

Section: Introductionmentioning

confidence: 99%

Direct evidence for selective modulation of psbA, rpoA, rbcL and 16S RNA stability during barley chloroplast development

1993

View full text Add to dashboard Cite

The turnover of RNAs encoded by seven different barley chloroplast genes was analyzed after treatment of barley shoots with tagetitoxin, a selective inhibitor of chloroplast transcription. Changes in RNA stability were examined during chloroplast development using basal and apical leaf sections of 4.5-day-old dark-grown seedlings and apical leaf sections of 4.0-day-old dark-grown seedlings which had been illuminated for 12 h. Of the RNAs examined, a 2.6 kb unspliced precursor of tRNA(lys) exhibited the shortest half-life, which was estimated to be 3 h. The 16S rRNA and psbA mRNA had the longest estimated half-lives, which were greater than 40 h. Among mRNAs, half-lives were estimated to range from 6 h for psaA mRNA, to over 40 h for psbA mRNA. Therefore, barley chloroplast mRNAs have long half-lives relative to bacterial mRNAs. The stability of atpB mRNA and the unspliced precursor of tRNA-lys was not altered during chloroplast development, while the stability of psaA mRNA decreased 2-fold. In contrast, the stability of the 16S rRNA and mRNAs for rpoA, psbA and rbcL increased during chloroplast development. The stability of 16S rRNA increased markedly during chloroplast development in the dark and this increase was maintained in illuminated seedlings. The stability of rbcL mRNA increased 2.5-fold during chloroplast development in the dark, and then decreased 2-fold in chloroplasts of light-grown plants. The initial increase in rpoA and psbA mRNA stability was also light-independent, with total increases in stability of at least 5-fold. In the case of rpoA, the stability of 2 of the 13 polycistronic rpoA transcripts that were detected in dark-grown plants was selectively increased during chloroplast development. In conclusion, the stability of some transcripts is selectively increased and further modulated during chloroplast development in barley. We propose that the selective stabilization of chloroplast mRNA, which occurred independent of light, is an indication that non-light regulated developmental signals are involved in barley chloroplast mRNA stability.

show abstract

“…Interestingly, transcriptional differences in several genes that are directly and indirectly involved in photosynthesis and starch metabolism had previously been reported between diploids and allotetraploid A. thaliana (Wang et al, 2006;Ni et al, 2009), and levels of the CO 2 -fixing enzyme Rubisco were reported to increase with an increase in ploidy in allopolyploid wheat (Triticum aestivum; Dean and Leech, 1982). However, allopolyploidy adds another complication in that organisms with genomic contributions from two or more species do not exhibit exclusively additive or predictably changing gene expression (Madlung et al, 2002;Wang et al, 2004;Chen, 2010;Matsushita et al, 2012).…”

mentioning

confidence: 96%

Environmental Regulation of Heterosis in the Allopolyploid Arabidopsis suecica

et al. 2016

View full text Add to dashboard Cite

Allopolyploids are organisms possessing more than two complete sets of chromosomes from two or more species and are frequently more vigorous than their progenitors. To address the question why allopolyploids display hybrid vigor, we compared the natural allopolyploid Arabidopsis suecica to its progenitor species Arabidopsis thaliana and Arabidopsis arenosa. We measured chlorophyll content, CO 2 assimilation, and carbohydrate production under varying light conditions and found that the allopolyploid assimilates more CO 2 per unit chlorophyll than either of the two progenitor species in high intensity light. The increased carbon assimilation corresponds with greater starch accumulation, but only in strong light, suggesting that the strength of hybrid vigor is dependent on environmental conditions. In weaker light A. suecica tends to produce as much primary metabolites as the better progenitor. We found that gene expression of LIMIT DEXTRINASE1, a debranching enzyme that cleaves branch points within starch molecules, is at the same level in the allopolyploid as in the maternal progenitor A. thaliana and significantly more expressed than in the paternal progenitor A. arenosa. However, expression differences of b-amylases and GLUCAN-WATER DIKINASE1 were not statistically significantly elevated in the allopolyploid over progenitor expression levels. In contrast to allopolyploids, autopolyploid A. thaliana showed the same photosynthetic rate as diploids, indicating that polyploidization alone is likely not the reason for enhanced vigor in the allopolyploid. Taken together, our data suggest that the magnitude of heterosis in A. suecica is environmentally regulated, arises from more efficient photosynthesis, and, under specific conditions, leads to greater starch accumulation than in its progenitor species.

show abstract

Genome Expression during Normal Leaf Development

Cited by 53 publications

References 9 publications

Why do leaves and leaf cells of N-limited barley elongate at reduced rates?

Why do leaves and leaf cells of N-limited barley elongate at reduced rates?

Direct evidence for selective modulation of psbA, rpoA, rbcL and 16S RNA stability during barley chloroplast development

Environmental Regulation of Heterosis in the Allopolyploid Arabidopsis suecica

Contact Info

Product

Resources

About