Systematic and functional analysis of non-specific lipid transfer protein family genes in sugarcane under Xanthomonas albilineans infection and salicylic acid treatment

Abstract

Plant non-specific lipid transfer proteins (nsLTPs) are small basic proteins that play a significant regulatory role in a wide range of physiological processes. To date, no genome-wide survey and expression analysis of this gene family in sugarcane has been performed. In this study we identified the nsLTP gene family in Saccharum spontaneum and carried out expression profiling of nsLTPs in two sugarcane cultivars (Saccharum spp.) that have different resistance to leaf scald caused by Xanthomonas albilineans (Xa) infection. The effect of stress related to exogenous salicylic acid (SA) treatment was also examined. At a genome-wide level, S. spontaneum AP85-441 had 71 SsnsLTP genes including 66 alleles. Tandem (9 gene pairs) and segmental (36 gene pairs) duplication events contributed to SsnsLTP gene family expansion. Five SsnsLTP proteins were predicted to interact with five other proteins. Expression of ShnsLTPI.8/10/Gb.1 genes was significantly upregulated in LCP85-384 (resistant cultivar), but downregulated in ROC20 (susceptible cultivar), suggesting that these genes play a positive regulatory role in response of sugarcane to Xa infection. Conversely, ShnsLTPGa.4/Ge.3 appears to act as a negative regulator in response Xa infection. The majority (16/17) of tested genes were positively induced in LCP85-384 72 h after SA treatment. In both cultivars, but particularly in LCP85-384, ShnsLTPIV.3/VIII.1 genes were upregulated at all time-points, suggesting that the two genes might act as positive regulators under SA stress. Meanwhile, both cultivars showed downregulated ShnsLTPGb.1 gene expression, indicating its potential negative role in SA treatment responses. Notably, the ShnsLTPGb.1 gene had contrasting effects, with positive regulation of gene expression in response to Xa infection and negative regulation induced by SA stress. Together, our results provide valuable information for elucidating the function of ShnsLTP family members under two stressors and identified novel gene sources for development of sugarcane that are tolerant of environmental stimuli.

Pathogenesis-Related 1 (PR1) Protein Family Genes Involved in Sugarcane Responses to Ustilago scitaminea Stress

“…Notably, the results of the current study are in line with those of recent studies, which demonstrated that gene duplication for acquiring new genes in this family genes was a common occurrence in sugarcane [ 26 , 27 , 28 ]. Due to the complex polyploid nature of sugarcane, functional divergence and redundancy is more frequent, and the unique retention profile of duplicated genes after the establishment of polyploidy might explain a general increase in biological complexity [ 29 ]. In addition to duplication events, the influence of polyploidy on mutation rates might also cause insertion–deletion events [ 30 ].…”

Identification of ARF transcription factor gene family and its defense responses to bacterial infection and salicylic acid treatment in sugarcane

“…Our data showed that some genes shared similar expression profiles, but some genes had different expression profiles under either Aaa or Xa infection, suggesting that sugarcane ARF family genes underwent functional divergence and redundancy in evolution. This phenomenon is frequent in plants, particularly in complex polyploidy crops such as sugarcane ( Li et al, 2022 ). Notably, some ARF genes (such as SpapARF02 ) showed similar functions in sugarcane defense responses to Aaa and Xa infections, while others (such as SpapARF01 ) played the opposite role in responses to both bacterial infections.…”

A Novel Non-Specific Lipid Transfer Protein Gene, CmnsLTP6.9, Enhanced Osmotic and Drought Tolerance by Regulating ROS Scavenging and Remodeling Lipid Profiles in Chinese Chestnut (Castanea mollissima Blume)

“…So far, the nsLTP gene family has been reported in many plant species, such as poplar (Populus L.) [37], sugarcane (Saccharum spp.) [23], foxtail millet (Setaria italica L.) [20], and Chinese white pear (Pyrus bretschneideri) [38]. Studies on the nsLTP gene family in chestnut have not been reported yet.…”

“…Lipids, as an important secondary metabolite, play a crucial role in plants' response to environmental stress, such as membrane stabilization, plant extracellular vesicle function, and cuticle and cell wall integrity [13][14][15][16]. In plants, considerable evidence shows that nsLTPs are involved in a range of lipid-related biological processes, including oil accumulation, cuticular wax deposition, pollen wall formation, and cutin synthesis [13,[17][18][19], while nsLTPs have also been found to respond to a variety of abiotic/biotic stresses, such as drought, high salinity, heat, cold stress, pathogen defense, PEG 6000 stress, and IAA and ABA stresses [20][21][22][23][24][25]. For abiotic stress, OsLTPL159 increased cold tolerance at the early seedling stage in rice [26].…”