Resveratrol improves the iron deficiency adaptation of Malus baccata seedlings by regulating iron absorption

Background Resveratrol (Res), a phytoalexin, has been widely reported to participate in plant resistance to fungal infections. However, little information is available on its role in abiotic stress, especially in iron deficiency stress. Malus baccata is widely used as apple rootstock in China, but it is sensitive to iron deficiency. Results In this study, we investigated the role of exogenous Res in M. baccata seedings under iron deficiency stress. Results showed that applying 100 μM exogenous Res could alleviate iron deficiency stress. The seedlings treated with Res had a lower etiolation rate and higher chlorophyll content and photosynthetic rate compared with the apple seedlings without Res treatment. Exogenous Res increased the iron content in the roots and leaves by inducing the expression of MbAHA genes and improving the H+-ATPase activity. As a result, the rhizosphere pH decreased, iron solubility increased, the expression of MbFRO2 and MbIRT1 was induced, and the ferric-chelated reductase activity was enhanced to absorb large amounts of Fe2+ into the root cells under iron deficiency conditions. Moreover, exogenous Res application increased the contents of IAA, ABA, and GA3 and decreased the contents of DHZR and BL for responding to iron deficiency stress indirectly. In addition, Res functioned as an antioxidant that strengthened the activities of antioxidant enzymes and thus eliminated reactive oxygen species production induced by iron deficiency stress. Conclusion Resveratrol improves the iron deficiency adaptation of M. baccata seedlings mainly by regulating iron absorption.

The Siberian wild apple, Malus baccata (L.) Borkh., is an additional contributor to the genomes of cultivated European and Chinese apples

It is crucial to understand domestication to unravel the evolutionary processes that shape the divergence of populations. Differences in life-history traits have probably led to marked differences in the mode and speed of evolution between trees and annuals, particularly the extent of crop-wild gene flow during domestication. Apple is an iconic tree and major fruit crop grown worldwide. The contribution of wild apple species to the genetic makeup of the cultivated apple genome remains a topic of intense investigations. We used population genomics in combination with SNPs to investigate the contributions of the two known wild apple relatives, Malus sylvestris and Malus sieversii, and a supposed contributor, Malus baccata, to European and Chinese rootstock and dessert genomes, with a focus on the extent of wild-crop gene flow during apple domestication. We showed that the European dessert and rootstock apples form a specific gene pool, whereas the Chinese dessert and rootstock apples were a mixture of three wild gene pools. Coalescent-based inferences and gene flow estimates indicated that M. baccata is an additional contributor to the genome of both European and Chinese cultivated apples through wild-to-crop introgressions. We also confirmed previous results on the contribution of M. sylvestris to the cultivated apple genome, and provided insights into the origin of the apple rootstock. This study further demonstrates the role of gene flow during apple domestication, as seen in other woody perennials, and show that domestication of the apple tree involved several wild apple species.

Antifungal Activity of Six Medicinal Plants of Pakistan Against Selected Fungi

Antifungal properties of Cucumis sativus, Portulaca oleracea, Malus baccata, Saxifraga flagillaris, Geranium wallichianum. and Monotheca buxifolia were evaluated against Alternaria, Acremonium, Verticillium, Pythium, and Trichoderma, using agar well-diffusion method. The crude ethanolic extract of G. wallichianum showed the highest antifungal activity followed by P. oleracae and S. flagillaris. The dichloromethane fraction of G. wallichianum showed the highest antifungal activity against Acremonium (28 mm), Alternaria (20.50 mm) and Trichoderma (20 mm). The n-hexane fraction of C. sativus showed the maximum antifungal activity (20 mm) against Pythium. The present findings demonstrated that six selected plants contain precious natural products for treating infectious diseases and can be used to isolate chemical compounds for future drug sources. Bangladesh J. Bot. 50(2): 441-443, 2021 (June)

Resveratrol Improves the Iron Deficiency Adaptation of Malus Baccata Seedlings by Regulating Iron Absorption, Phytohormone Content, and ROS Migration

Resveratrol (Res), a phytoalexin, has been widely reported to participate in plant resistance to fungal infections. However, little information is available on its role in abiotic stress, especially in iron deficiency stress. Malus baccata is widely used as apple rootstock in China, but it is sensitive to iron deficiency. In this study, we investigated the role of exogenous Res in M. baccata seedings under iron deficiency stress. Results showed that applying 100 µmol exogenous Res could alleviate iron deficiency stress. The seedlings treated with Res had a lower etiolation rate and higher chlorophyll content and photosynthetic rate compared with the apple seedlings without Res treatment. Exogenous Res increased the iron content in the roots and leaves by inducing the expression of MbAHA genes and improving the H+-ATPase activity. As a result, the rhizosphere pH decreased, iron solubility increased, the expression of MbFRO2 and MbIRT1 was induced, and the ferric-chelated reductase activity was enhanced to absorb large amounts of Fe2+ into the root cells under iron deficiency conditions. Moreover, exogenous Res application increased the contents of IAA, ABA, and GA3 and decreased the contents of DHZR and BL for responding to iron deficiency stress indirectly. In addition, Res functioned as an antioxidant that strengthened the activities of antioxidant enzymes and thus eliminated reactive oxygen species production induced by iron deficiency stress. These findings are expected to enhance the application and examination of the physiological role of Res under iron deficiency stress in apples.