Xue Chenyang, Gao Yingmei, Qu Bo, Tai Peidong, Guo Cheng, Chang Wenyue, Zhao Guanghui
College of Biological Technology, Shenyang Agricultural University, Shenyang, China.
Liaoning Key Laboratory of Biological Invasions and Global Changes, Shenyang Agricultural University, Shenyang, China.
Front Plant Sci. 2021 Jul 29;12:696687. doi: 10.3389/fpls.2021.696687. eCollection 2021.
Hybridization is one of the important factors influencing the adaptive evolution of invasive plants. According to previous studies, hybridization with an invasive plant reduces the adaptability of its native congener to environment. However, in this study, the hybridization with an invasive plant of (LT) improves the tolerance and accumulation of its native congener (CR) to cadmium (Cd). Under Cd stress, ♀ × ♂ (ZCR) showed higher biomass and Cd accumulation. Compared with CR, ZCR has longer vegetative and reproductive growth time. Moreover, ZCR adopted more reasonable biomass allocation strategy. ZCR increased the proportion of reproductive allocation and ensured its own survival with the increase of Cd stress. Furthermore, ZCR increased the translocation of Cd to aboveground parts and changed the distribution of Cd. A large amount of Cd is stored in senescent leaves and eliminated from the plant when the leaves fall off, which not only reduces the Cd content in the plant, but also reduces the toxicity of Cd in the normal leaves. Transcriptome analysis shows a total of 2055 (1060 up and 995 down) differentially expressed genes (DEGs) were detected in the leaves of Cd-stressed ZCR compared with CR, while only 792 (521 up and 271 down) were detected in ♀ × ♂ (ZLT) compared with LT. A large number of DGEs in ZCR and ZLT are involved in abscisic acid (ABA) synthesis and signal transduction. The genes induced by ABA in ZCR, including CNGC5/20, CPK1/28, CML, PTI1-like tyrosine-protein kinase 3, respiratory burst oxidase homolog protein C, and WRKY transcription factor 33 were found differentially expressed compared CR. carotenoid cleavage dioxygenase 4, NCED1/2, phytoene synthase 2, and CYP707A involved in ABA synthesis and decomposition in ZLT were found differentially expressed compared LT. We speculated that ABA played an important role in Cd transportation of hybrids and Cd distribution in senescent and normal leaves. The results demonstrate that hybridization with an invasive plant improves the adaptability of the hybrid to Cd stress and may enhance the extinction risk of native congener in pollution environment.
杂交是影响入侵植物适应性进化的重要因素之一。根据以往的研究，与入侵植物杂交会降低其本地同属植物对环境的适应性。然而，在本研究中，与入侵植物（LT）杂交提高了其本地同属植物（CR）对镉（Cd）的耐受性和积累能力。在镉胁迫下，♀×♂（ZCR）表现出更高的生物量和镉积累量。与CR相比，ZCR的营养生长和生殖生长时间更长。此外，ZCR采用了更合理的生物量分配策略。随着镉胁迫的增加，ZCR增加了生殖分配比例并确保了自身的存活。此外，ZCR增加了镉向地上部分的转运并改变了镉的分布。大量的镉储存在衰老叶片中，并在叶片脱落时从植物中排出，这不仅降低了植物中的镉含量，也降低了正常叶片中镉的毒性。转录组分析表明，与CR相比，镉胁迫下的ZCR叶片中共检测到2055个（1060个上调和995个下调）差异表达基因（DEG），而与LT相比，♀×♂（ZLT）中仅检测到792个（521个上调和271个下调）。ZCR和ZLT中的大量差异表达基因参与脱落酸（ABA）的合成和信号转导。与CR相比，ZCR中由ABA诱导的基因，包括CNGC5/20、CPK1/28、CML、类PTI1酪氨酸蛋白激酶3、呼吸爆发氧化酶同源蛋白C和WRKY转录因子33被发现差异表达。与LT相比，ZLT中参与ABA合成和分解的类胡萝卜素裂解双加氧酶4、NCED1/2、八氢番茄红素合酶2和CYP707A被发现差异表达。我们推测ABA在杂种的镉转运以及衰老叶片和正常叶片中的镉分布中起重要作用。结果表明，与入侵植物杂交提高了杂种对镉胁迫的适应性，并可能增加污染环境中本地同属植物的灭绝风险。
