Acta Horticulturae Sinica ›› 2021, Vol. 48 ›› Issue (2): 254-264.doi: 10.16420/j.issn.0513-353x.2020-0285

• Research Papers • Previous Articles     Next Articles

Studies on the Regreening Mechanism of the Iron-deficiency Chlorosis Leaves induced by GA3 in‘Whangkeumbae’(Pyrus pyrifolia Nakai)

JIA Bing, GUO Guoling, WANG Youyu, YE Zhenfeng, LIU Li, LIU Pu, HENG Wei, ZHU Liwu*()   

  1. College of Horticulture,Anhui Agricultural University,Hefei 230036,China
  • Received:2020-06-06 Revised:2020-08-27 Online:2021-02-25 Published:2021-03-09
  • Contact: ZHU Liwu


In order to reveal the regreening effect and physiological mechanism of the iron-deficiency chlorosis leaves induced by GA3,the iron-deficiency chlorosis and normal plants of‘Whangkeumbae’(Pyrus pyrifolia Nakai)were used as the experiment materials,and GA3 solutions of 50,100,200 and 400 mg · L-1 was sprayed on chlorosis leaves during the growth period. The contents of Fe,GA3,GA4,IAA and JA in leaves were determined,the chloroplast ultrastructure was observed and photographed under an electron microscope,and the expression levels of genes related to Fe metabolism or GA signal transduction were analyzed by fluorescence quantitative PCR. The results showed that on the 9th day after treatment with exogenous GA3,the chlorosis leaves showed different degrees of regreening,with obvious vein regreening and partial body regreening. On the 12th day of treatment with 400 mg · L-1 GA3,the regreening of chlorosis leaves were the most obvious. The Fe content in regreening leaves were significantly higher than that in control with water on the 9th and 12th day after GA3 treatment. Exogenous GA3 could induce the expressions of FER1,FER2,FER3,FRO2,IRT1 and FD1 in chlorosis leaves. On the 12th day,the expression levels of FER2 and IRT1 in each treatment were more than 10 and 40 times higher than that in the control group,indicating that exogenous GA3 promoted the expression of genes related to iron storage,reduction and transport in leaves. Exogenous GA3 treatment significantly increased the contents of endogenous GA3 and GA4 in leaves and rapidly induced the expression of GID11 and GID13. Among them,the expression level of GID11 was 76.45 times higher than that of the control group on the 3rd day after the treatment with 50 mg · L-1 GA3. On the 12th day after treatment with 400 mg · L-1 GA3,the thylakoid granule lamellae in leaves were clearer than that of chlorosis leaves,with fewer fractured lamellae. The results preliminarily revealed regreening mechanism of chlorosis leaves induced by GA3 in‘Whangkeumbae’.

Key words: pear, leaf regreening, Fe metabolism, GA transduction gene, qRT-PCR

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