| Biochar\|induced accumulation of ABA in Arabica coffee seedlings regulates stomatal conductance in response to drought stress |
|
View Fulltext View/Add Comment Download reader |
| |
| DOI：10.7606/j.issn.1000-7601.2025.05.04 |
| Key Words: Arabica coffee seedlings drought stress biochar ABA stomatal regulation gene expression profiles |
| Author Name | Affiliation | | SHAO Zhongsi | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China
Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, Hainan 570216, China | | YU Haohao | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China
Institute of Tropical and Subtropical Cash Crops, Yunnan Academy of Agricultural Sciences, Baoshan, Yunnan 678000, China | | DONG Xiangshu | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China | | ZHAO Hao | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China | | YANG Yuntian | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China | | GAO Jing | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China | | HE Feifei | School of Agriculture, Yunnan University, Kunming, Yunnan 650500, China |
|
| Hits: 588 |
| Download times: 236 |
| Abstract: |
| 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. |
|
|
|