Multilocation comparison of fruit composition for ‘HoneySweet’, an RNAi based plum pox virus resistant plum

Abstract

‘HoneySweet’, a transgenic plum (Prunus domestica) resistant to plum pox virus through RNAi, was deregulated in the U.S. in 2011. The compositional study of ‘HoneySweet’ fruit was expanded to include locations outside of the US as well as utilizing a wide variety of comparators and different collection years to see the variability possible. The results revealed that plums have a wide variation in composition and that variation among locations was greater than variation among cultivars. This was also the case for different years at one location. The results supported the supposition that the transgene and insertion event had no significant effect on the composition of ‘HoneySweet’ fruit even under virus pressure, and that it fell in the normal range of composition of commercially grown plums. It also suggested that the effect of environment is as great as that of genetics on the fruit composition of plums.

Defining the ‘HoneySweet’ insertion event utilizing NextGen sequencing and a de novo genome assembly of plum (Prunus domestica)

“…Heat maps were constructed from the TPM values for the unique reads (Tables S5 and S6 ). These show the variation between each tree sampled is for the most part, greater than the variation by cultivar similar to that seen when sampling fruit composition from these trees 10 .…”

Three strategies of transgenic manipulation for crop improvement

“…According to the survey carried out by ISAAA (2022), most (227) of the singular transgenic events (265) approved for commercial release worldwide were developed by the first strategy: 210 by bacterial genes (Stalker et al, 1988;Ye et al, 2000;Paine et al, 2005;Castiglioni et al, 2008;Napier et al, 2019), 8 by exogenous genes from mold, algae, fungus, and yeast (Knutzon et al, 1998;Napier et al, 2019;Kinney et al, 2022), 5 by exogenous genes from sexually incompatible plant species (Song et al, 2003;Takagi et al, 2005;Preuss et al, 2012;Rice et al, 2014), and 2 by the mutant copies of the endogenous genes for enhancing herbicide tolerance (McNaughton et al, 2008;EFSA Panel on Genetically Modified Organisms [GMO]et al, 2018;Karthik et al, 2020), respectively (Table 1). Thirty-eight events were developed by the third strategy and transformed by synthetic sequences transcribing antisense or double-stranded RNAs for suppressed expression of undesirable endogenous genes of pathogens, pest insects, and recipient crops themselves (Chen et al, 2003;Davis and Ying, 2004;Tennant et al, 2005;Otani et al, 2007;Ilardi and Nicola-Negri, 2011;Aragao et al, 2013;Ramaseshadri et al, 2013;Carvalho et al, 2015;Orbegozo et al, 2016;Borah et al, 2018;Wu et al, 2018;Callahan et al, 2019;Chiozza et al, 2020). Only one event was transformed by endogenous genes for restoring male fertility (Unger et al, 2002) and another event for pyramiding herbicide tolerance.…”

“…Similar to drought tolerance, the vast majority of the transgenic events overexpressing endogenous disease-resistant genes or homologous disease-resistant genes from sexually incompatible species remain at the testing stage (Anand et al, 2003;Zhao et al, 2005;Yang et al, 2008;Zhou et al, 2009). Twenty-five of the 29 approved events have been developed by the third strategy and transformed with synthetic DNA sequences to transcribe antisense or double-stranded RNAs for the interference of disease viruses (Chen et al, 2003;Davis and Ying, 2004;Tennant et al, 2005;Aragao et al, 2013;Carvalho et al, 2015; 10.3389/fpls.2022.948518 Borah et al, 2018;Wu et al, 2018;Callahan et al, 2019;Chiozza et al, 2020), and only the other four potato events are transformed with exogenous genes of pathogenesis-related proteins from distant species of the nightshade family (Solanum bulbocastanum and Solanum venturii) (Table 1; Halterman et al, 2008;Foster et al, 2009). RNA interference (RNAi) triggered by antisense or double-stranded RNAs described by transformed synthetic DNA sequences is a versatile, effective, safe, and ecofriendly technology for crop protection against viruses and other pathogens as well as insect pests, and delaying maturation of fruits with positive economic, environmental, and human health implications (Klee, 1993;Taning et al, 2020;Giudice et al, 2021;Hernández-Soto and Chacón-Cerdas, 2021).…”

Transgenic Improvement for Biotic Resistance of Crops

“…According to the survey carried out by ISAAA (http: //www.isaaa.org/gmapprovaldatabase/default.asp, accessed on 22 September 2022), twenty-five transgenic events of bean, papaya, plum, potato, squash, sweet pepper, and tomato resistant to pathogenic viruses were generated and authorized for cultivation and market (Table 2). All of them were transformed by double-stranded sequences transcribing the coat protein, replicase, or helicase of the pathogenic viruses themselves for RNAi [94,[100][101][102]. In recent years, clustered regularly interspaced short palindromic repeats-cas (CRISPR/Cas) technology and its new advances attracted much attention in transgenic improvement for rival resistance [103][104][105][106].…”