PROTOPLASMA ：河南農大丨高溫干旱脅迫致ABA和ROS積累影響水稻萌發

期刊：PROTOPLASMA

主題：高溫和干旱脅迫導致水稻脫落酸和活性氧的積累，抑制種子萌發生長

標題：High temperature and drought stress cause abscisic acid and reactive oxygen species accumulation and suppress seed germination growth in rice.

影響因子：2.633

檢測指標：Ca2+、H2O2流速

檢測部位：水稻胚芽鞘出苗位點

Ca2+、H2O2流速流實驗處理方法：

種子分別在高溫38攝氏度，20％PEG-6000處理5天

Ca2+、H2O2流速流實驗測試液成份：

0.1 mM CaCl2, 0.1 mM KCl,0.3mM MES, pH 6.0

作者：河南農業大學趙全志、劉娟

英文摘要

Seed germination is one of the most important biological processes in the life cycle of plants, and temperature and water are the two most critical environmental factors that influence seed germination.

In the present study, we investigated the roles of the plant hormone abscisic acid (ABA) and reactive oxygen species (ROS) in high temperature (HT) and drought-induced inhibition of rice seed germination. HT and drought stress caused ABA accumulation in seeds and inhibited seed germination and seedling establishment. Quantitative real-time polymerase chain reaction analysis revealed that HT and drought stress induced the expression of OsNCED3, a key gene in ABA synthesis in rice seeds.

In addition, ROS (O2?- and H2O2) and malondialdehyde contents were increased in germinating seeds under HT and drought stress. Moreover, we adopted the non-invasive micro-test technique to detect H2O2 and Ca2+ fluxes at the site of coleoptile emergence. HT and drought stress resulted in a H2O2 efflux, but only drought stress significantly induced Ca2+ influx. Antioxidant enzyme assays revealed that superoxide dismutase (SOD), peroxidase, catalase (CAT), and ascorbate peroxidase (APX) activity were reduced by HT and drought stress, consistent with the expression of OsCu/ZnSOD, OsCATc, and OsAPX2 during seed germination.

Altogether, these results suggest that ABA and ROS accumulation under HT and drought conditions can inhibit rice seed germination and growth.

 中文摘要

種子萌發是植物生命周期中最重要的生物過程之一，溫度和水是影響種子萌發的兩個最關鍵的環境因素。

在本研究中，我們研究了植物激素脫落酸（ABA）和活性氧（ROS）在高溫（HT）和干旱誘導的水稻種子萌發抑制中的作用。 HT和干旱脅迫導致種子中ABA積累，抑制種子萌發和幼苗建立。定量實時聚合酶鏈反應分析表明，HT和干旱脅迫誘導水稻種子ABA合成中關鍵基因OsNCED3的表達。

此外，在HT和干旱脅迫下，萌發種子中ROS（O2? - 和H2O2）和丙二醛含量增加。此外，我們采用非侵入性微測試技術檢測胚芽鞘出現部位的H2O2和Ca2+通量。 HT和干旱脅迫導致H2O2流出，但只有干旱脅迫才能顯著誘導Ca2 +流入。抗氧化酶測定表明，HT和干旱脅迫使超氧化物歧化酶（SOD），過氧化物酶，過氧化氫酶（CAT）和抗壞血酸過氧化物酶（APX）活性降低，與種子萌發過程中OsCu / ZnSOD，OsCATc和OsAPX2的表達一致。

總之，這些結果表明，在HT和干旱條件下ABA和ROS的積累可以抑制水稻種子的萌發和生長。

結果表明：干旱脅迫顯著加劇了發芽種子中胚芽鞘出苗位點的Ca2+凈吸收（圖b），Ca2+凈吸收量比對照種子高61.2％。同時，HT對Ca2+凈流入沒有顯著影響，盡管與對照相比略有下降。 H2O2流速在對照組和治療組之間的方向和大小上顯示出顯著差異（圖c）。對照種子表現出H2O2的吸收。然而，在HT和干旱脅迫下，H2O2從種子外排到測試溶液中，分別達到1.20和0.44pmol cm-2 s -1。這些結果可能表明H2O2外排進一步意味著在HT和干旱脅迫下發芽種子中積累更多的H2O含量。

文章鏈接： 

https://link.springer.com/article/10.1007%2Fs00709-019-01354-6

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