Alteration of antioxidant enzymes activities in the leaf of bermudagrass after treated with nitric oxide (NO) donor and inhibitor under cold stress.

<p>(A) Activities of superoxide dismutase (SOD); (B), Activities of peroxidase (POD), (C) Activities of catalase (CAT). Experiments were repeated for three times, and means were average values of activities of SOD, POD and CAT, respectively. Independent-samples <i>t</i> test was used to determine statistical differences. <i>Bars</i> show standard deviation. Different letters indicate statistical difference significance at <i>P</i> < 0.05 among the treatments. CK was control that treated with sterilized water; SNP was plant treated with SNP, P+L was plant treated with PTIO and L-NAME. FW was fresh weight.</p

Expression pattern of genes in leaves of bermudagrass with different treatment under cold stress.

<p>(A) Expression of <i>POD</i>. (B) Expression of <i>SOD</i>. (C) Expression of <i>CAT</i>. (D) Expression of <i>LEA</i>. (E) Expression of <i>CBF</i>. Total RNA were isolated from leaves treated at 4°C for 6, 12, 24, and 48 h, respectively. Quantitative real time PCR was repeated for three times. Independent-samples <i>t</i> test was used to determine statistical differences. Bars show standard deviation.</p

Alteration of performance index (PI) that deduced by JIP-test analysis of fluorescence transients.

<p>Calculations of each parameter refer to the method of Yusuf et al. (2010). (A) Alteration of PI for energy conservation from exciton to the reduction of PSI end acceptors (<i>PI</i>_<i>Total</i>). (B) Alteration of PI for energy conservation from exciton to the reduction of intersystem electron (<i>PI</i>_<i>ABS</i>). Experiments were repeated for three times, and means were average values of the parameters. Independent-samples <i>t</i> test was used to determine statistical differences. <i>Bars</i> show standard deviation. Different letters indicate statistical difference significance at <i>P</i> < 0.05 among the treatments. CK was control that treated with sterilized water, SNP was plant treated with SNP, P+L was plant treated with PTIO and L-NAME. 30 means the culture temperature of 30°C, and 4 means the culture temperature of 4°C.</p

Expression pattern of genes in leaves of bermudagrass with different treatment under cold stress.

<p>(A) Expression of <i>POD</i>. (B) Expression of <i>SOD</i>. (C) Expression of <i>CAT</i>. (D) Expression of <i>LEA</i>. (E) Expression of <i>CBF</i>. Total RNA were isolated from leaves treated at 4°C for 6, 12, 24, and 48 h, respectively. Quantitative real time PCR was repeated for three times. Independent-samples <i>t</i> test was used to determine statistical differences. Bars show standard deviation.</p

Basic photosynthetic parameters of the OJIP transient curves.

<p>Values were listed as Mean ± SD. Independent-samples <i>t</i> test was used to determine statistical differences. Different letters indicate statistical difference significance at <i>P</i> < 0.05 among the treatments. NT means normal temperature (30°C), and LT means low temperature (4°C). CK was control that treated with sterilized water, SNP was plant treated with SNP, P+L was plant treated with PTIO and L-NAME.</p><p>Basic photosynthetic parameters of the OJIP transient curves.</p

Alteration of quantum yields and efficiencies/probabilities that deduced by JIP-test analysis of fluorescence transients.

<p>Calculations of each parameter refer to the method of Yusuf et al. (2010). (A) Alteration of maximum quantum yield for primary photochemistry (<i>φP</i>_<i>0</i>). (B) Alteration of quantum yield of the electron transport flux from Q_A to Q_B (<i>φE</i>_<i>0</i>). (C) Alteration of efficiency/probability with that a PSII trapped electron is transferred from Q_A to Q_B (<i>ΨE</i>_<i>0</i>). (D) Alteration of efficiency/probability with which an electron from Q_B is transferred until PSI acceptors (<i>ΨR</i>_<i>0</i>). Experiments were repeated for three times, and means were average values of the parameters. Independent-samples <i>t</i> test was used to determine statistical differences. <i>Bars</i> show standard deviation. Different letters indicate statistical difference significance at <i>P</i> < 0.05 among the treatments. CK was control that treated with sterilized water; SNP was plant treated with SNP, P+L was plant treated with PTIO and L-NAME. 30 means the culture temperature of 30°C, and 4 means the culture temperature of 4°C.</p

Alteration of energy fluxes per active PSII reaction center (RC) that deduced by JIP-test analysis of fluorescence transients.

<p>Calculations of each parameter refer to the method of Yusuf et al. (2010). (A) Alteration of absorbed photon flux per RC (<i>ABS/RC</i>). (B) Alteration of electron flux reducing end electron acceptors at PSI acceptor side per RC (<i>RE</i>_<i>0</i><i>/RC</i>). Experiments were repeated for three times, and means were average values of the parameters. Independent-samples <i>t</i> test was used to determine statistical differences. <i>Bars</i> show standard deviation. Different letters indicate statistical difference significance at <i>P</i> < 0.05 among the treatments. CK was control that treated with sterilized water, SNP was plant treated with SNP, P+L was plant treated with PTIO and L-NAME. 30 means the culture temperature of 30°C, and 4 means the culture temperature of 4°C.</p

Alteration of chlorophyll fluorescence transients in bermudagrass leaves after treated with nitric oxide (NO) donor and inhibitor under cold stress.

<p>(A) Alteration of chlorophyll fluorescence transients after different treatments under normal temperature (30°C). (B) Alteration of chlorophyll fluorescence transients after different treatments under low temperature (4°C).</p

Primers used for expression of genes.

<p>F and R represent forward and reverse, respectively.</p><p>Primers used for expression of genes.</p

Alteration of chlorophyll content of bermudagrass after treated with nitric oxide (NO) donor and inhibitor under cold stress.

<p>Experiments were repeated for three times, and means were average values of chlorophyll content. Independent-samples <i>t</i> test was used to determine statistical differences. <i>Bars</i> show standard deviation. Different letters indicate statistical difference significance at <i>P</i> < 0.05 among the treatments. CK was control that treated with sterilized water, SNP was plant treated with SNP, P+L was plant treated with PTIO and L-NAME. FW was fresh weight.</p