| 邵忠思,喻好好,董相书,赵颢,杨云天,高晶,何飞飞.生物炭诱导小粒咖啡幼苗积累ABA调节气孔导度响应干旱胁迫[J].干旱地区农业研究,2025,(5):34~46 |
| 生物炭诱导小粒咖啡幼苗积累ABA调节气孔导度响应干旱胁迫 |
| Biochar\|induced accumulation of ABA in Arabica coffee seedlings regulates stomatal conductance in response to drought stress |
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| DOI：10.7606/j.issn.1000-7601.2025.05.04 |
| 中文关键词: 小粒咖啡幼苗 干旱胁迫 生物炭 ABA 气孔调节 基因表达 |
| 英文关键词:Arabica coffee seedlings drought stress biochar ABA stomatal regulation gene expression profiles |
| 基金项目:云南省重大科技专项计划(202202AE090002)；云南大学第十四届研究生科研创新项目（KC-22221772） |
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| 中文摘要: |
| 为明确施用生物炭对中度干旱胁迫下小粒咖啡幼苗形态、气孔调节、脱落酸（abscisic acid，ABA）激素水平及ABA信号通路相关基因表达量的影响，研究设置了4个处理：T1，正常供水（55%~60%土壤最大持水量）+不施用生物炭；T2，中度干旱（30%~35%土壤最大持水量）+不施用生物炭；T3，中度干旱（水分处理同T2）+5%干土质量生物炭；T4，正常供水（水分处理同T1）+5%干土质量生物炭。试验时期设置为D1（干旱1 d），D15（干旱15 d），D30（干旱30 d），D60（干旱60 d），R30（干旱60 d后复水30 d，复水后保持幼苗正常供水）。结果表明：（1）与T1相比，T2和T3的气孔导度（stomatal conductance，Gs）在D30时分别显著下降了75%和50%，D60时T2和T3的净光合速率（photosynthetic rate，Pn）分别显著下降了62.4%和48.4%；D15时气孔长度分别下降了15.4%和3.7%，显著降低了气孔宽度，气孔密度分别上升了40.0%和37.8%，且气孔器变小；T4的ABA相对含量显著大于T1。（2）中度干旱胁迫下小粒咖啡叶片中的ABA含量呈先升高后降低、复水后再次升高的趋势，且中度干旱能诱导CaNCED家族大部分基因的表达，T3处理的CaNCED家族基因相对表达量和ABA相对含量均显著高于T2处理，其中D15时，ABA相对表达量显著增加19.6%；相较于T2、T3的ABA受体，CaPYL4和CaPYL8在D30时段表达量最高，分别提高114.1%和135.8%；中度干旱胁迫促进CaPP2C50、CaPP2C16-likeX2、CaPP2C16-like和CaPP2C24在叶片中的表达，CaSnRK2家族大部分基因都参与表达，其中，相较于T2，T3处理CaSAPK7的相对表达量在D30、D60和R30时段均分别显著增加204.4%、189.0%、88.3%；中度干旱诱导ABF家族大部分基因的表达，D30时段参与表达的基因最多。综上，正常灌水条件下添加生物炭能促进ABA在小粒咖啡叶片中的积累；中度干旱胁迫下添加生物炭能维持小粒咖啡叶片中ABA较高水平，对ABA信号通路的转导有更好的诱导作用，从而调节气孔来提高小粒咖啡的抗干旱胁迫能力；CaNCED6、CaNCED8可能是参与小粒咖啡ABA合成的潜在基因。 |
| 英文摘要: |
| This study aimed to clarify the effects of biochar application on the morphology, stomatal regulation, abscisic acid (ABA) hormone levels, and the expression levels of ABA signaling pathway\|related genes in young coffee seedlings under moderate drought stress. Four treatments were set up: T1, normal water supply (55%~60% of the maximum soil water holding capacity) + no application of biochar; T2, moderate drought (30%~35% of the maximum soil water holding capacity) + no application of biochar; T3, moderate drought (water treatment the same as T2) + 5% dry soil mass biochar; T4, normal water supply (water treatment the same as T1) + 5% dry soil mass biochar. The experimental period was set as D1 (drought for 1 day), D15 (drought for 15 days), D30 (drought for 30 days), D60 (drought for 60 days), and R30 (rehydration for 30 days after 60 days of drought; rehydration maintained normal water supply for the seedlings). The results showed that, (1) Compared with T1, the stomatal conductance (Gs) of T2 and T3 decreased significantly by 75% and 50%, respectively, at D30; the net photosynthetic rate (Pn) of T2 and T3 decreased significantly by 62.4% and 48.4%, respectively, at D60; the stomatal length decreased by 15.4% and 3.7%, respectively, at D15; the stomatal width reduced significantly; the stomatal density increased by 40.0% and 37.8%, respectively, and the stomatal apparatus became smaller. The relative content of ABA in the leaves of T4 was significantly higher than that of T1. (2) Under moderate drought stress, the ABA content in the leaves of small coffee plants showed a trend of first increasing, then decreasing, and then increasing again after rehydration, and moderate drought could induce the expression of most genes in the CaNCED family. The relative expression levels of CaNCED family genes in the T3 treatment were significantly higher than those in the T2 treatment, and at D15, the relative expression level of ABA was significantly higher than 19.6%. Compared with T2, the expression levels of ABA receptors CaPYL4 and CaPYL8 in the T3 treatment were the highest at D30, being 114.1% and 135.8%, respectively. Moderate drought stress promoted the expression of CaPP2C50, CaPP2C16-likeX2, CaPP2C16-like, and CaPP2C24 in the leaves, and most genes of the CaSnRK2 family were involved in the expression. Compared with T2, the relative expression level of CaSAPK7 in the T3 treatment was significantly higher at the D30, D60, and R30 periods, being 204.4%, 189.0%, and 88.3%, respectively. Moderate drought stress induced the expression of most genes of the ABF family, and the period with the most genes involved in expression was D30. In summary, biochar addition under normal watering conditions can promote the accumulation of ABA in the leaves of small coffee plants; biochar addition under moderate drought stress can maintain a higher level of ABA in the leaves of small coffee plants, have a better induction effect on the transduction of the ABA signaling pathway, and thereby regulate stomata to improve the drought stress resistance of small coffee plants. CaNCED6 and CaNCED8 may be potential genes involved in the synthesis of ABA in small coffee plants. |
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