香蕉苯丙氨酸解氨酶基因家族的全基因組鑒定及表達分析

楊會曉 孫媛媛 賈彩紅 金志強 徐碧玉 王卓

摘 ?要??苯丙氨酸解氨酶（Phenylalanine ammonia-lyase， PAL）是催化苯丙烷代謝途徑第1步反應的限速酶，廣泛地參與植物生長發育過程中的各種生理活動。本研究通過生物信息學分析，從香蕉A基因組數據庫中利用BLASTp篩選出53個可能的MaPAL編碼蛋白序列。在NCBI分析蛋白保守結構域，發現僅有8個基因具有典型的PAL家族基因的特性。聚類分析結果表明香蕉MaPAL家族的8個基因可以分為Class I 和Class II兩類。轉錄組數據表明，所有MaPAL基因在果實發育階段高表達，MaPAL5參與果實采后成熟過程。在干旱、低溫、鹽處理的香蕉幼苗葉片中，MaPAL1、MaPAL2、MaPAL3、MaPAL4和MaPAL5成員均顯著上調表達，MaPAL6號成員顯著下調表達，這些成員參與香蕉響應上述非生物脅迫過程。8個MaPAL成員在枯萎病菌處理下均顯著下調表達，表明在感病品種巴西蕉根系中，MaPAL基因的表達全部被Foc TR4抑制。本研究結果為分析MaPAL基因家族在香蕉果實品質形成和響應逆境中的作用提供了理論依據。

關鍵詞 ?香蕉;苯丙氨酸解氨酶;系統進化分析;表達分析;基因家族中圖分類號??S668.1??????文獻標識碼??A

Identification and Expression Analysis of Phenylalanine Ammonia-lyase Gene Family in Banana

YANG Huixiao^1，2， SUN Yuanyuan^1，2， JIA Caihong¹， JIN Zhiqiang^1，2， XU Biyu¹， WANG Zhuo^1*

1. Institute of Tropical Bioscience and Biotechnology， Chinese Academy of Tropical Agricultural Sciences / Key Laboratory of Tropical Biotechnology， Ministry of Agriculture and Rural Affairs， Haikou， Hainan 571101， China; 2. College of Horticulture， Nanjing Agricultural University， Nanjing， Jiangsu 210095， China

Abstract ?Phenylalanine ammonia-lyase gene （PAL） is one of the key enzymes associated with plant growth and stress resistance in the secondary metabolism pathway. In this study， we used four L-phenylalanine ammonia-lyase genes inArabidopsis thalianaas qurry and acquired 53 candidate PAL gene sequences by BLASTp in banana A genome database. And then we used conserved domain search of NCBI， only 8 gene members were found containing?typical PAL domain in the protein sequence. In?the?phylogenetic tree， eight?PALs could be classified into 2 groups， Class I and Class II. The transcriptome data showed that allMaPALgenes were highly expressed at fruit development stages. AndMaPAL5was differential expression in banana fruit postharvest stages. Under the drought， low temperature and salt stresses，MaPAL1，?MaPAL2，MaPAL3，MaPAL4andMaPAL5members were up-regulated andMaPAL6was?down-regulated. All 8MaPALswere down-regulated under the Foc TR4 infection. The results suggested that allMaPAL genes played?important roles in banana fruit development and ripenning， responding to abiotic and biotic stresses. This study would provide a theoretical basis for further exploration the function of MaPALs?in banana fruit ripening and under stresses.

Keywords ?banana; phenylalanine ammonia-lyase; phylogenetic analysis; expression analysis; gene family

DOI10.3969/j.issn.1000-2561.2019.10.007

香蕉是多年生草本植物，是重要的熱地亞熱帶經濟作物。其果實富含淀粉和黃酮類物質，是人們重要的糧食和營養來源^[1]。在香蕉生長過程中，幼苗會經常受到各種非生物和生物脅迫的影響，如干旱、低溫、鹽^[2-3]和枯萎病^[4]，嚴重地影響香蕉果實的產量和品質。尤其是香蕉枯萎病，由于抗病育種無法滿足香蕉產業的需求，且沒有有效的化學防治手段，造成香蕉栽培面積不斷地減少^[5]。……