Zhenlin Wang

Interactions between polyamines and ethylene during grain filling in wheat grown under water deficit conditions

This study was to test the hypothesis that polyamines (PAs) and ethylene may be involved in mediating the effect of water deficit on grain filling. Two wheat cultivars, drought-tolerant Shannong16 (SN16) and drought-sensitive Jimai22 (JM22), were used and subjected to well-watered and severe water deficit (SD) during grain filling. SD reduced the weight of superior and inferior grains, by 7.38 and 23.54xa0% in JM22, 13.8 and 2.2xa0% in SN16, respectively. Higher free-spermidine (Spd) and free-spermine (Spm) concentration and lower free-putrescine (Put) concentration, ethylene evolution rate (EER) and 1-aminocylopropane-1-carboxylic acid (ACC) concentration were found in superior grains than those in inferior ones. Opposite to the variations of Spd and Spm concentration, ACC, Put concentration and EER were significantly increased under SD. The percentage variation of PAs and ACC differed with cultivars and grain types. ACC concentration of superior and inferior grains under SD increased significantly at 21xa0days post-anthesis, by 90 and 164xa0% in JM22, 65 and 13.2xa0% in SN16, respectively. The equivalent value of Put concentration was 1.04 and 7.9xa0% in JM22, 34.4 and 10.3xa0% in SN16. Spd concentration of superior grains showed a higher decrease than that of inferior ones in both cultivars, while Spm exhibited an opposite trend between both grain types. These percentage variations were highly consistent with the differed responses of weight of both grain types to SD in JM22 and SN16. Grain filling rate was negatively correlated with EER and ACC concentration, while positively correlated with Spd and Spm concentration as well as the ratio of Spd or Spm to ACC. Exogenous Spd or aminoethoxyvinylglycine (an inhibitor of ethylene synthesis by inhibiting ACC synthesis) obviously reduced ACC concentration and EER and increased Spd and Spm concentration, while exogenous ethephon (an ethylene-releasing agent) or methylglyoxal-bis (an inhibitor of Spd and Spm synthesis) showed the opposite effects. The results suggested that it would be good for wheat to have the physiological traits of higher Spd and Spm, as well as a higher Spd/ACC or Spm/ACC, under SD.

Application of nitric oxide and calcium nitrate enhances tolerance of wheat seedlings to salt stress

Nitric oxide and calcium are two kinds of signaling molecules that are the key secondary messenger. An experiment was conducted in saline culture solution to examine the cross-talk interactions of nitric oxide and calcium in common wheat under NaCl stress. Addition of 100xa0mM NaCl reduced plant growth, decreased the chlorophyll content and root activity, increased the reactive oxygen species (such as

Manipulation of lignin metabolism by plant densities and its relationship with lodging resistance in wheat

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Activities of key enzymes involved in starch synthesis in grains of wheat under different irrigation patterns

O2·- and H2O2) level, lipid peroxidation and electrolyte leakage, and suppressed the activities of antioxidant enzymes in wheat seedlings. Moreover, high Na+ resulted in the deficiency of mineral nutrients. While addition of 0.10xa0mM sodium nitroprusside (a NO donor) and/or 17.50xa0mM Ca(NO3)2 (Na/Caxa0=xa05) alleviated a decline in chlorophyll content, root activity and soluble sugar content, stimulated the activities of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and decreased the electrolyte leakage, lipid peroxidation, H2O2 content,

Involvement of ethylene and polyamines biosynthesis and abdominal phloem tissues characters of wheat caryopsis during grain filling under stress conditions

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Effects of new coated release fertilizer on the growth of maize

O2·- generation rate. Furthermore, the concentrations of potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe) and copper (Cu) concentrations in the leaves and roots of wheat were increased, indicating that application of Ca(NO3)2 facilitated the maintenance of ion homeostasis, while the exogenous NO improved the uptake of Ca. The results suggest that the nitric oxide and calcium are effective in alleviating the adverse effects of salt stress: the nitric oxide is more actively involved in antioxidant system while the calcium is more beneficial to ion homeostasis. When applied in combination, Ca(NO3)2 could counteract the toxicity of exogenous NO to the root, while the exogenous NO may promote the selectivity of uptake and transport of Ca2+.