Levels of indole-3-acetic acid in intact and decapitated coleoptiles as determined by a specific and highly sensitive solid-phase enzyme immunoassay

The insecticidal efficacy of Bt cotton under different environments has generated controversy in recent years. The objective of this study was to investigate possible reasons of the conflicting results caused by temperature stress. Two different types of Bt transgenic cotton cultivars (a Bt cultivar, Sikang1, and an hybrid Bt cultivar, Sikang3) were selected. The plants of the two Bt cultivars were exposed to high temperature (37°C), low temperature (18°C), and the control (27°C) for short (24 h) and long (48 h) periods of stress at peak boll stage, and then moved to the glasshouse where the control plants were maintained. The results showed that the leaf insecticidal toxin content fully recovered within 24 h to the level of control after the end of short duration high-temperature treatment, and recovered mostly within 48 h of the termination of 24 h low-temperature stress. Under long duration high temperature treatment the Bt toxin content required longer recovery periods (48 and 72 h for Sikang3 and Sikang1, respectively) to reach the control level. The Bt protein content only recovered partially at 96 h after the end of the long-duration low-temperature stress, and the concentrations of the Cry1Ac protein were 74% and 77% of the corresponding control for Sikang1 and Sikang3, respectively. The different recovery and increase slowly of the leaf nitrogen metabolic rates after ceasing the heat and cold stress may be possible reason for the above difference. In summary, the duration and type of temperature (cold or heat) stress may cause different Bt insecticidal protein recovery rate due to different recovery rate of enzymes.

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“…The absorbance was recorded at 490 nm. Calculation of the ELISA data was performed as described by Weiler et al (1981).…”

Section: Cry1ac Protein Concentration Assaymentioning

confidence: 99%

The recovery of Bt toxin content after temperature stress termination in transgenic cotton

Chen

Wen²,

Zhang

et al. 2013

Span. j. agric. res.

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“…This antibody was tested to specifically recognize free IAA (Weiler et al, 1981). Kernels were prefixed in 3% (w/v) EDAC (Sigma) and 0.1 M PBS, postfixed in 4% paraformaldehyde in the same buffer, and embedded in Paraplast as described above.…”

Section: Iaa Localizationmentioning

confidence: 99%

ZmPIN1-Mediated Auxin Transport Is Related to Cellular Differentiation during Maize Embryogenesis and Endosperm Development

2009

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To study the influence of PINFORMED1 (PIN1)-mediated auxin transport during embryogenesis and endosperm development in monocots, the expression pattern of the three identified ZmPIN1 genes was determined at the transcript level. Localization of the corresponding proteins was also analyzed during maize (Zea mays) kernel development. An anti-indole-3-acetic acid (IAA) monoclonal antibody was used to visualize IAA distribution and correlate the direction of auxin active transport, mediated by ZmPIN1 proteins, with the actual amount of auxin present in maize kernels at different developmental stages. ZmPIN1 genes are expressed in the endosperm soon after double fertilization occurs; however, unlike other tissues, the ZmPIN1 proteins were never polarly localized in the plasma membrane of endosperm cells. ZmPIN1 transcripts and proteins also colocalize in developing embryos, and the ZmPIN1 proteins are polarly localized in the embryo cell plasma membrane from the first developmental stages, indicating the existence of ZmPIN1-mediated auxin fluxes. Auxin distribution visualization indicates that the aleurone, the basal endosperm transfer layer, and the embryo-surrounding region accumulate free auxin, which also has a maximum in the kernel maternal chalaza. During embryogenesis, polar auxin transport always correlates with the differentiation of embryo tissues and the definition of the embryo organs. On the basis of these reports and of the observations on tissue differentiation and IAA distribution in defective endosperm-B18 mutant and in N-1-naphthylphthalamic acid-treated kernels, a model for ZmPIN1-mediated transport of auxin and the related auxin fluxes during maize kernel development is proposed. Common features between this model and the model previously proposed for Arabidopsis (Arabidopsis thaliana) are discussed.

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“…Color development in each well was detected using an ELISA Reader (model EL310, Bio-TEK, Winooski, VT) at optical density A 490 . Z, ZR, IAA, GAs, and ABA contents were calculated following Weiler et al (1981). The results are the means Ϯ se of at least four replicates.…”

mentioning

confidence: 99%

Hormonal Changes in the Grains of Rice Subjected to Water Stress during Grain Filling

et al. 2001

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Lodging-resistant rice (Oryza sativa) cultivars usually show slow grain filling when nitrogen is applied in large amounts. This study investigated the possibility that a hormonal change may mediate the effect of water deficit that enhances whole plant senescence and speeds up grain filling. Two rice cultivars showing high lodging resistance and slow grain filling were field grown and applied with either normal or high amount nitrogen (HN) at heading. Well-watered and water-stressed (WS) treatments were imposed 9 days post anthesis to maturity. Results showed that WS increased partitioning of fixed 14 CO 2 into grains, accelerated the grain filling rate but shortened the grain filling period, whereas the HN did the opposite way. Cytokinin (zeatin ϩ zeatin riboside) and indole-3-acetic acid contents in the grains transiently increased at early filling stage and WS treatments hastened their declines at the late grain filling stage. Gibberellins (GAs; GA 1 ϩ GA 4 ) in the grains were also high at early grain filling but HN enhanced, whereas WS substantially reduced, its accumulation. Opposite to GAs, abscisic acid (ABA) in the grains was low at early grain filling but WS remarkably enhanced its accumulation. The peak values of ABA were significantly correlated with the maximum grain filling rates (r ϭ 0.92**, P Ͻ 0.01) and the partitioning of fixed 14 C into grains (r ϭ 0.95**, P Ͻ 0.01). Exogenously applied ABA on pot-grown HN rice showed similar results as those by WS. Results suggest that an altered hormonal balance in rice grains by water stress during grain filling, especially a decrease in GAs and an increase in ABA, enhances the remobilization of prestored carbon to the grains and accelerates the grain filling rate.

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Levels of indole-3-acetic acid in intact and decapitated coleoptiles as determined by a specific and highly sensitive solid-phase enzyme immunoassay

Cited by 301 publications

References 22 publications

The recovery of Bt toxin content after temperature stress termination in transgenic cotton

The recovery of Bt toxin content after temperature stress termination in transgenic cotton

ZmPIN1-Mediated Auxin Transport Is Related to Cellular Differentiation during Maize Embryogenesis and Endosperm Development

Hormonal Changes in the Grains of Rice Subjected to Water Stress during Grain Filling

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