The grains are commonly used for the preparation of a fermented sourdough bread known as “injera,” as well as for straw, feed, and to reinforce the walls of mud huts. The available genetic diversity in Ethiopia has driven breeding programs to improve existing varieties and meet market demand and consumers’ specifications ( Ayalew et al., 2011 Assefa et al., 2015). Traditionally, it is grown by small-scale farmers therefore, thousands of locally adapted accessions have been developed ( Report on Area and Production Major Crops, 2012). It originated in Ethiopia, where it is considered a staple crop, and the number one cereal produced in the country ( Seyfu, 1993). Tef is an allotetraploid cereal with a chromosome number of 20 (AB 2n = 4x = 40), and its subgenomes are relatively small (∼300 Mb), with high gene density and low transposable element content ( VanBuren et al., 2020). Furthermore, these crops have a wealth of nutritional qualities and desirable traits that enhance their adaptability to climate change ( Padulosi et al., 2012), and much more fundamental research is required to better understand them as a potential source of sustainable food production. Most of these traditional crops offer an opportunity to improve agricultural production and maintain sustainable food security. Examples for underutilized cereals are broomcorn millet ( Panicum miliaceum L.), canary seed ( Phalaris canariensis L.), and tef, which are monocotyledonous plants in the family of Poaceae (grasses), the same as the abovementioned staple crop ( Bekkering and Tian, 2019). Approximately 50% of plant-based caloric intake is obtained from three primary grain sources-rice, wheat, and maize, while most traditional species are neglected and underutilized. However, the commercialization of conventional agriculture has led to concentrating on only a few of these crops, which must be examined critically to ensure reliable food supply even with current population growth and climate change ( Awika, 2011 Curtis and Halford, 2014). The world depends on many crop species to sustain the food supply. These findings can facilitate the discovery of insect-resistance genes leading to enhanced yield in tef and other cereal crops. This is the first report to reveal the variation in the defense mechanisms of tef plants. A transcriptomic time-series analysis of a selected accession RTC-144 infested with aphids revealed a massive alteration of genes related to specialized metabolism that potentially synthesize non-volatile toxic compounds. Overall, we found that the tef plants possess similar defense responses as other Poaceae family species, while the non-volatile deterrent compounds are yet to be characterized. The volatile analysis exposed a rich and dynamic metabolic profile, and the central metabolism profile indicated that tef plants adjust their sugars and organic and amino acid levels. To determine chemical responses, the volatile and central metabolite profiles were measured upon aphid attack for 4 days. This was negatively correlated with aphid performance. As a physical barrier, the density of non-granular trichomes was evaluated, in which a higher number of trichomes on the RTC-406 than on the other accessions was observed. To highlight the variation in defense responses, we investigated the physical and chemical mechanisms. While the number of aphid progeny was lower on RTC-406 than on the other two, the aphid olfactory assay indicated that the aphids tended to be repelled from the RTC-144 accession. We compared the differences in Rhopalosiphum padi (Hemiptera Aphididae) aphid performance, preference, and feeding behavior between the three accessions. To discover the main pests of tef in the Mediterranean climate, we conducted an insect field survey on three selected accessions named RTC-144, RTC-405, and RTC-406, and discovered that the most abundant insect order is Hemiptera. In this study, we aimed to classify the insect abundance on tef crop in Israel, and to elucidate its chemical and physical defense mechanisms in response to insect feeding. Crop cultivation in new geographic regions raises questions regarding the molecular basis for biotic stress responses. Tef ( Eragrostis tef), a staple crop that originated in the Horn of Africa, has been introduced to multiple countries over the last several decades.
0 Comments
Leave a Reply. |