低温胁迫下不同浓度ABA对4个油棕新品种幼苗生理特性的影响

刘艳菊 周丽霞 曹红星

摘  要：探讨低温胁迫下不同品种油棕幼苗ABA合成酶基因NCED3表达特性及不同浓度ABA对其幼苗生长和生理的影响，为提高不同品种油棕幼苗抗寒能力提供理论依据。以油棕新品种Ni、C×N、B×E、D×N为材料，对其进行低温胁迫处理（15、10、5 ℃，5 d），利用实时荧光定量PCR（qPCR）检测4种油棕幼苗的NCED3基因表达特性;然后，10 ℃低温胁迫下对4种油棕幼苗外施不同浓度ABA（50～300 μmol/L ABA），测定其可溶性蛋白、可溶性糖、脯氨酸含量和超氧化物歧化酶（SOD）及过氧化物酶（POD）活性等生理指标。结果表明，低温胁迫可触发4种油棕幼苗ABA合成酶基因NCED3的過量表达，外施50～300 μmol/L ABA均降低幼苗质膜透性和SOD酶活性，抑制MDA和H₂O₂含量上升，缓解低温胁迫引起的膜脂过氧化，提高可溶性蛋白、可溶性糖含量和POD活性，进而提高油棕幼苗抗寒性。4个品种中，B×E材料的耐寒能力较强。

关键词：油棕;ABA;低温胁迫中图分类号：S31      文献标识码：A

Effects of Exogenous ABA on Physiology of Four New Oil PalmVarieties under Cold Stress

LIU Yanju^1，2， ZHOU Lixia^1，2， CAO Hongxing^1，2*

1. Coconut Research Institute， Chinese Academy of Tropical Agricultural Sciences， Wenchang， Hainan 571339， China; 2. Hainan Key Biological Laboratory of Tropical Oil Crops， Wenchang， Hainan 571339， China

Abstract： In order to provide theoretical basis for improving cold resistance of different oil palm varieties， the present experiment was conducted to investigate the expression characteristics of ABA synthase geneNCED3of different oil palm varieties under cold stress and the growth and physiology effects of different ABA concentrations on cold resistance of different oil palm varieties. The new oil palm varieties Ni， C×N， B×E and D×N were used as the materials， treated with low temperature stress （15 ℃， 10 ℃， 5 ℃， 5 d）. The expression characteristics ofNCED3in the seedlings were detected by real-time quantitative PCR （qPCR）. Then， different concentrations of ABA （50-300 μmol/L ABA） were applied to the seedlings under 10 ℃， and the physiological indexes were determined， including soluble protein content， soluble sugar content， proline content， H₂O₂content， MDA content， SOD and POD activity. Cold stress could trigger the overexpression of ABA synthase geneNCED3 in the seedlings. The application of 50-300 μmol/L ABA decreased the plasma membrane permeability and SOD activity of the seedlings， inhibited the increase of MDA and H₂O₂levels， so the membrance lipid peroxidation caused by cold stress was relieved， soluble protein， soluble sugar content and POD activity were increased， and thus improved cold resistance of the seedlings. B×E had strong cold tolerance.

Keywords： oil palm; ABA; cold stress

DOI： 10.3969/j.issn.1000-2561.2020.06.008

油棕（Elaeis guineensisJacq.）属棕榈科（Palmae）多年生热带木本油料作物，被誉为“世界油王”^[1]，在我国主要分布于海南、云南、广东、广西等地。油棕喜高温，在热量不足的环境下生长缓慢，因此，低温成为限制其产量提高和种植面积进一步扩大的主要因子之一。目前，国内关于油棕抗寒的研究多集中在描述油棕生理生化反应方面^[2-4]，而关于提高油棕抗寒能力的研究较少。

ABA作为植物生产中广泛应用的一种植物激素和信号分子，能促进器官衰老和脱落、调节基因表达等作用。低温胁迫下，ABA与植物受体蛋白的结合能力增强，感知和传递低温胁迫信号，从而调控植物体内各物质的平衡和诱导植物的胁迫抗性^[5]。……