Photosynthesis, Carbohydrate Metabolism, and Yield of Phytochrome-B-Overexpressing Potatoes under Different Light Regimes

Abstract

amount of light energy absorbed by the green foliage, the efficiency of the foliage to use the energy captured Transgenic potatoes (Solanum tuberosum L.) overexpressing Arafor biomass production, and the partitioning of the crop bidopsis thaliana (L.) Heynh. phytochrome B (phyB) have been reported to exhibit a substantially modified plant architecture, increased biomass to the harvested plant part. Because potato has photosynthetic performance, reduced photoinhibition, delayed leaf one of the highest harvest indices of major crops and senescence, and increased tuber yield. A greenhouse and a growth there may be little potential for significant shifts in total chamber experiment were conducted at Braunschweig, Germany, to biomass accumulation, genotypes with superior net phoelucidate the crop physiological basis for the yield differences between Abbreviations: CER, carbon exchange rate; CER max , light-saturated

Effects of auxins on in vitro reserve compounds of Phalaenopsis amabilis (Orchidaceae)

“…According to Debergh and Maeno (1981), roots developed in vitro are not functional, but the biochemical analysis of roots of P. amabilis cultured in vitro shows accumulation of organic compounds that could be remobilized and translocated to newly formed tissue. Reduced levels of total soluble protein, from 350 to 125 mgg -1 dry weight, were also observed in pho-tosynthetic leaves of wild and transgenic potato grown ex vitro for 120 days (Schittenhelm et al, 2004), and this phenolmenon was related to the end of the growth cycle with remobilization of compounds to the storage organ. Silveira et al (2004) observed that intracellular protein levels increased during the growth phase cells of Pinus taeda L. in suspension culture of embryos when 2,4-D (0.44 mg L -1 ) was added to the medium and the starch levels were simultaneously reduced.…”

“…Roots of cultivated potato showed the amount of total carbohydrates of 50 mgg -1 dry weight at 20 days (Schittenhelm et al, 2004), but P. amabilis roots showed 240 mgg -1 dry matter when treated with IBA (0.2 mgL -1 ) for 30 days and approximately 100 mgg -1 dry matter when treated with IBA (5.0 mgL -1 ) or 2,4-D (0.032 and 0.160 mgL -1 ) for 120 days, both at concentrations four times higher than in potato. Starch levels in roots ranged from 100 mgg -1 dry weight after treatment with 5.0 mg L -1 IBA at 120 days to almost 280 mgg -1 dry matter (0.2 mg L -1 IBA at 120 days).…”

“…Therefore, increased ability to remobilize organic compounds (soluble carbohydrates, starch and total soluble protein) to perform specific tasks and coordinate developmental programs based on the availability of these crucial nutrients may increase the survival (Gibson, 2005) and growth of these explants when they are transferred from the in vitro stage to ex vitro, as observed in Oxalis tuberosa Mol (Conner et al, 1993) and Rosa (Capellades et al, 1991). Schittenhelm et al (2004) observed that the starch from leaves of wild potato (Solanum tuberosum L.) and transgenic potato grown in a greenhouse were reduced from 20 to 120 days, showing nearly complete translocation of these reserves from the tubers during the growth cycle. To comprehend source-sink regulation in relation to plant development and to be able to manipulate these complex interactions for agricultural purposes (Wardlaw, 1990;Williams et al, 2000;Lemoine et al, 2013), it is vital that the underlying induction factors determining a sink organ for sugar (competition/priority system among growing tissues and storage) be correlated with growth regulators, sugar-sensing mechanisms, and the physiological process of sugar transport, and their cellular and temporal expression patterns must be defined.…”

Effects of saline irrigation water and proline applications on yield, vegetative and physiological characteristics of potato crop (Solanum tuberosum L.)

“…Pre-sprouting was done on tubers and tubers containing one sprout were chosen to plant so that variation as a result of sprouting was diminished. After emergence, each pot was fertilized weekly using solution containing as much as 120 mgL -1 N, 120 mgL -1 P, 170 mgL -1 K and 20 mgL -1 Mg (Schittenhelm et al, 2004). The data were analyzed statistically by using SAS and the means were compared using Tukey test (Bek and Efe, 1988).…”

Development of transgenic crops based on photo‐biotechnology

“…In addition, photosynthetic carbon dioxide fixation was more efficient in the transgenic lines than the wild type. Moreover, the overexpression of Arabidopsis PHYB in the potato plants caused semi-dwarfism, with decreased apical dominance, increased chlorophyll accumulation, markedly elongated tubers and stronger anthocyanin pigmentation (Thiele et al 1999;Boccalandro et al 2003;Schittenhelm et al 2004). Using PHYB sense and antisense transformants, it was established that overexpression of PHYB resulted in photoperiod sensitive tuber formation, while suppression of PHYA increased the frequency of tuberization (Yanovsky et al 2000).…”