| Water shortage and farmland drought stress are key factors in sustainable development of north agricultural production and grain yield.Physiological and ecological basis of crop injuries made by water stress,the molecular mechanism of crop drought and improve crop drought-resistance are have been great attention for people.Here,potted method was adopted to study the impact of different degrees of water stress on physiological ecology,and molecular mechanisms in winter wheat seedling and potatoes water use efficiency in tillering stage.The results show that:(1)ABA contents responsive to soil water loss increased rapidly and showed a significantly negative correlation with the stomatal conductance and the leaf water potential and a significantly positive correlation with the leaf-air temperature difference,respectively.The continuous accumulation of ABA was resulted mainly from the increased transcripts of both TaNCEDs and TaBGs genes.The transcripts of TaCYP707A1 and TaGT declined sharply from 85%to 65%RSM and then increased from 65%to 35%RSM,indicating that ABA metabolism not only accelerates the accumulation of ABA level but also contributes to maintain ABA homeostasis.In conclusion,the macroscopic-microscopic changes responsive to water deficient reflects the ABA-regulated,drought-resistance coordinate mechanisms at physiological,ecological and molecular levels in triticum aestivum.(2)With the increase of relative soil moisture stress,ABA content and StNCEDs gene transcription level in leaves gradually increased in potato tillering period with the relative soil moisture from 25%to 85%range.At the RSM25%,ABA content increased by 33%and expression of StNCEDl improved four times,while expression of StNCED2 improved 9 times.Stomatal conductance showed the biggest decline was at RSM45%,down 81%.At the same time of daily variation,RSM45%had the highest water use efficiency.When at noon 12:00 and afternoon 18:00 RSM45%reached the peak,respectively 1.13μmol.mmol-1 and 1.15 μmol.mmol-1. |
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