State Key Laborary of Agrobiotechnology, Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing, 100193, China.
Plant J. 2020 Aug;103(5):1783-1795. doi: 10.1111/tpj.14863. Epub 2020 Jul 21.
Drought is an environmental factor that can severely influence plant development and distribution, and greatly affect the yield and economic value of crops. We characterized CmBBX19, a BBX family subgroup IV member gene, from the transcriptome database of Chrysanthemum morifolium in response to drought stress. Drought stress and ABA treatments downregulated the expression of CmBBX19. We generated CmBBX19-overexpressing (CmBBX19-OX) lines and CmBBX19-suppressing lines (CmBBX19-RNAi), and found that suppressed expression of CmBBX19 led to enhanced drought tolerance compared with the wild-type (WT) controls, while CmBBX19-OX lines exhibited reduced drought tolerance. Downstream gene analysis showed that CmBBX19 modulates drought tolerance mainly through inducing changes in the expression of ABA-dependent pathway genes, including protective protein, redox balance and cell wall biogenesis genes, such as responsive to ABA 18, peroxidase 12, and cellulose synthase-like protein G2. Moreover, CmBBX19 was shown to interact with CmABF3, a master ABA signaling component, to suppress expression of these downstream genes. We conclude that BBX19-ABF3 module functions in the regulation of drought tolerance of chrysanthemum through an ABA-dependent pathway.
干旱是一种环境因素，它会严重影响植物的发育和分布，并极大地影响作物的产量和经济价值。我们从菊花转录组数据库中鉴定出了一个 BBX 家族亚家族 IV 成员基因 CmBBX19，该基因响应干旱胁迫。干旱胁迫和 ABA 处理下调 CmBBX19 的表达。我们生成了 CmBBX19 过表达（CmBBX19-OX）系和 CmBBX19 抑制系（CmBBX19-RNAi），发现与野生型（WT）对照相比，抑制 CmBBX19 的表达导致增强了对干旱的耐受性，而 CmBBX19-OX 系则表现出降低的耐旱性。下游基因分析表明，CmBBX19 主要通过诱导 ABA 依赖途径基因的表达变化来调节耐旱性，包括保护性蛋白、氧化还原平衡和细胞壁生物发生基因，如响应 ABA 18、过氧化物酶 12 和纤维素合酶样蛋白 G2。此外，CmBBX19 被证明与 CmABF3 相互作用，CmABF3 是 ABA 信号成分的主要成分，以抑制这些下游基因的表达。我们得出结论，BBX19-ABF3 模块通过 ABA 依赖途径在菊花的耐旱性调节中发挥作用。
