查看更多>>摘要：Drought and high temperature stress affect chickpea growth and productivity。 Often these stresses occur simultaneously in the field and lead to a wide range of molecular and metabolic adaptations。 Two chickpea varieties; GPF2 (heat sensitive) and PDG4 variety (heat tolerant) were exposed to 35 C for 24 h individually and along with drought stress。 Five heat responsive signalling genes and 11 structural genes were analyzed using qPCR along with untargeted metabolites analysis using GC MS。 Expression of antioxidant genes (CaSOD and CaGPX， CaAPX and CaCAT)， transcription factors (CaHSFB2， CaHSFB2A， CaHSFB2B， CaHSP17。5 and CaHSP22。7) and signalling genes (CaCAM， CaGAD， and CaMAPK) were upregulated in GPF2 as compared to PDG4 variety。 Principal component analysis (PCA)， partial least-square discriminant analysis (PLS-DA)， and heat map analysis were applied to the metabolomics data to identify the differential response of metabolites in two chickpea va-rieties。 GC-MS analysis identified 107 and 83 metabolites in PDG4 and GPF2 varieties respectively。 PDG4 variety accumulated more sugars， amino acids， sugar alcohols， TCA cycle intermediates which provided heat resistance。 Additionally， the differential metabolic pathways involved in heat tolerance were alanine， aspartate， and glutamate metabolism， pantothenate CoA biosynthesis， fructose and mannose metabolism and pentose phosphate pathway in PDG4 variety。 There was less accumulation of metabolites in the primed plants of both varieties as compared to the non-primed plants indicating less damage due to heat stress。 The present study gives an overview of the molecular changes occurring in response to heat stress in sensitive and tolerant chickpea。
Mandizvo, TakudzwaOdindo, Alfred OduorMashilo, JacobMagwaza, Lembe Samukelo...
18页
查看更多>>摘要：Long-term cultivation of citron watermelon under water -constrained environments in sub-Saharan Africa resulted in the selection and domestication of highly tolerant genotypes。 However， information on the magnitude of variation for drought tolerance in citron watermelon is limited for the effective selection of suitable genotypes for breeding。 The objective of this study was to determine variation for drought tolerance among South African citron watermelon landrace accessions for selection and use as genetic stock for drought-tolerance breeding in this crop and closely-related cucurbit crops。 Forty genetically differentiated citron watermelon accessions were grown under non-stress (NS) and drought-stress (DS) conditions under glasshouse environment。 Data of physiological (i。e。， leaf gas exchange and chlorophyll fluorescence parameters) and morphological traits (i。e。， shoot and root system architecture traits， and fruit yield) were collected and subjected to various parametric statistical analyses。 The accessions varied significantly for assessed traits under both NS and DS conditions which aided classification into five groups， namely; A (highly drought-tolerant)， B (drought-tolerant)， C (moderate drought tolerant)， D (drought-sensitive) and E (highly drought-sensitive)。 Drought-tolerant genotypes produced more fruit yield with less water compared with drought-sensitive genotypes。 Several physiological and morphological parameters correlated with fruit yield under DS condition namely: instantaneous water -use efficiency (r = 0。97)， leaf dry weight (r = 0。77)， total root length (r = 0。46) and root dry weight (r = 0。48)。 The following accessions， namely: WWM-46， WWM-68， WWM-41(A)， WWM-15， WWM-64， WWM-57， WWM-47， WWM-37(2)， WWM-79， WWM-05 and WWM-50) were identified as highly drought-tolerant and recommended for drought-tolerance breeding in this crop or related cucurbit crops such as sweet dessert watermelon。
查看更多>>摘要：Heterologous expression of plant genes is becoming an important strategy for the improvement of specific traits in existing cultivars。 This study presents the response of a salt-sensitive high-yielding wheat variety under stress inducible expression of barley HVA1 gene belonging to the Late embryogenesis abundance (LEA) gene family。 Six homozygous transgenic wheat plants were developed and advanced for testing under various water regimes and salt stress conditions。 Putative transgenic plants showed better germination and root shoot development at the early developmental stages under drought stress conditions。 Moreover， transgenic plants illustrated higher values of physiological features as compared to non-transgenic plants under both drought and salinity stresses that indicate improved physiological processes in transgenic plants。 Higher membrane stability index (MSI) and lower electrolyte leakage (EL) after exposure to abiotic stresses reveal improved cellular membrane stability (CMS) and reduced injury to chloroplast membrane。 Interestingly， under salinity stress， transgenic wheat plants showed preference towards higher K(+ )accumulation in the shoot， which is not a well-understood HVA1 mediated Na+ avoidance mechanism under excessive subsurface salts。 The predisposition of K+/Na+ under salt stress conditions on heterologous expression of the HVA1 gene in wheat needs to be studied in detail in further studies。
NSTL
Elsevier