‘月月粉’月季PP2C家族基因鉴定及非生物胁迫响应分析

Genome-wide Identification and Abiotic Stress Response Analysis of PP2C Family Genes in Rosa chinensis‘Old Blush’

利用生物信息方法从月季‘月月粉’(Rosa chinensis‘Old Blush’)基因组中共鉴定出69个PP2C家族成员,其编码氨基酸的长度在122~1082 aa之间,等电点介于4.03~9.34,大部分蛋白呈亲水性。系统进化树分析将其分为12个亚族,同一亚族内基因结构和保守基序具有较高的相似性。基因片段复制事件是PP2C家族基因扩张的主要原因。启动子顺式作用元件分析表明约85%的月季PP2C含有逆境应答元件、激素应答元件等,推测其在响应逆境胁迫的过程中发挥重要作用。月季PP2C基因的表达具有组织和发育时期特异性,且部分基因参与干旱和高温胁迫响应过程,其中3个A亚族基因在干旱胁迫中响应明显,1个A亚族基因和2个G亚族基因在高温胁迫中响应明显。通过qRT-PCR分析11个不同亚族PP2C基因在月季失水胁迫和ABA处理下的表达模式,发现6个A亚族基因(RC0G0099200、RC1G0458700、RC1G0569200、RC2G0066800、RC2G0089100和RC5G0571100)和1个G亚族基因(RC3G0083700)的表达量显著升高,表明这些基因可能受ABA诱导并参与植物失水胁迫响应。

A total of 69 members of the PP2C family were identified from the genome of Rosa chinensis‘Old Blush’using bioinformatics techniques.The majority of the proteins were hydrophilic,and the amino acid lengths ranged from 122 to 1082 amino acids,with isoelectric points ranging 4.03 and 9.34.Phylogenetic analysis indicated that PP2Cs were divided into 12 subfamily groups,and the genetic structure and conserved motif of the same subfamily had a high similarity.Segmental duplication events were the main reason for the expansion of PP2C family genes.A significant function for the PP2C family of genes in response to stress may be inferred from the prediction of the cis-elements of promoters,which revealed that nearly 85%of PP2Cs had stress response elements and phytohormone response elements.The expression of rose PP2Cs was specific in tissue and developmental stage,and some genes were involved in the response to drought and high-temperature stress.Among them,three members of subgroup A were significantly responsive to drought stress,one member of subgroup A and two members of subgroup G were significantly responsive to high-temperature stress.Using qRT-PCR,the expression patterns of 11 PP2Cs genes under ABA and dehydration treatment were examined.Six subgroup A genes(RC0G0099200,RC1G0458700,RC1G0569200,RC2G0066800,RC2G0089100 and RC5G0571100)and a subgroup G gene(RC3G0083700)showed significantly higher expression levels following two treatments,suggesting that these genes may be activated by ABA and take part in the dehydration response.