Carbohydrate and Amino Acid Dynamics during Grain Growth in Four Temperate Cereals under Well-Watered and Water-Limited Regimes

Round 1

Reviewer 1 Report

Review for Agronomy.

Carbohydrate and amino acid dynamics during grain growth in four temperate ceareals under well-watered amd water-limited regimes.

Comments: The manuscript has good results, scientific quality and deals with a current and important theme related to food production i.e. food security and climate change. The results help to understand the physiological and biochemical mechanisms linked to drought tolerance.

Important data is in the complementary data and if the space permits could be transferred to the main body of the work.

In the introduction it is necessary to further detail the target area where it is intended to produce under water stress, with the genetic material used is adapted.

Comments:

Line 27: Avoid the use of the word productivity in greenhouse conditions, because it usually refers to field conditions at a certain plant density. Can use grain weight per plant.

Most of the bibliographic citations are not recent. There should be more recent citations with drought and metabolites or gas exchange with annual graniferous (including pseudocereals) species.

L30: Include the word drought and metabolites in the keywords.

L32: Insert bibliographic citations on cereal production under water stress.

L32/33. What about the target área?

L37. Any specific citation on photosynthesis in aristas?awl

L43. Check the review on proline in the journal Trends in Plant Science vol.15 n.2.

L58: Include the citation

Grain yield(32-36), physiological traits (36-39), and chemical quality in grains (Silva et al 2020).

L91: Justify why 80 and 40% of the water holding capacity were chosen as treatments in relation to the target area.

L87: Justify the substrate composition in relation to target área.

L99: What were the phenological phases gas Exchange were evaluated.

L172., respecatively (Fig.1). This difference in the cycle may impair the comparations of the parameters studied with the other species because it is in an late phenological phase.

Lines 188/189. The figures have difficult visualization when printed when comparing the differences between irrigated treatments and water stress. On the computer we can increase the figures for easy viewing. If a easier way to view is possible it would be convenient.

L232. Table 1 is not decrypting whether lowercase letters comcant rows or columns. If the letters compare columns one is not comparing the water regimes.

L262.  In the table 2, In place of grain yield, use grain weight per plant.

L 265/266. In the table 2, letters referring to the statistical analysis for the AB and SN parameters may be exchanged.

L317. The main axes for the main components shall contain the percentages explained by each axis.

L343. Grain weight per spike.  On the other hand, barley allows greater water reduction than wheat ( Ghahraman et al 1997).

Ghahraman, B., Sepaskhah, A. Use of a water deficit sensitivity index for partial irrigation scheduling of wheat and barley. Irrig Sci 18, 11–16 (1997). https://doi.org/10.1007/s002710050039

Those papers may be useful:

Estela R. Andrade. Vinıcius N. Ribeiro. Cleber V. G. Azevedo. Alisson F. Chiorato. Thomas C. R. Williams. Sergio A. M. Carbonell.  Biochemical indicators of drought tolerance in the common bean (Phaseolus vulgaris L.). Euphytica 2016.

Soares, G.F.; Ribeiro Júnior,W.Q.;  Pereira,L.F.; Lima, C.A.; Soares,D.S.; Muller,O.; Rascher,U.; Ramos, M.L.G. Characterization of wheat genotypes for drought tolerance and water use efficiency. Sci. Agric. v.78, n.5, e20190304, 2021.

Silva,A.N.; Ramos,M.L.G,; Ribeiro Júnior,W.Q.; Alencar, E.R.; Silva,P.C.;  Lima,C.A.; Vinson, C.C.; Silva,M.A.V. Water stress alters physical and chemical quality in grains of common bean, triticale and wheat. Agricultural water mnagement, Volume 231, 31 march 2020.

Vanessa do Rosário Rosa, Adinan Alves da Silva, Danielle Santos Brito, José Domingos Pereira Júnior, Cíntia Oliveira Silva, Maximiller Dal-Bianco, Juraci Alves de Oliveira and Cleberson Ribeiro. Drought stress during the reproductive stage of two soybean lines. Pesq. agropec. bras., Brasília, v.55, e01736, 2020.

Ghahraman, B., Sepaskhah, A. Use of a water deficit sensitivity index for partial irrigation scheduling of wheat and barley. Irrig Sci 18, 11–16 (1997). https://doi.org/10.1007/s002710050039

Author Response

Thank you for your comments. We addressed all the comments and modifications to the manuscript are indicated in blue.

Author Response File: Author Response.pdf

Reviewer 2 Report

The current study investigated the impact of water stress on metabolite (WSCs, AAs and nitrogen) dynamics between the source and sink organs in triticale, bread wheat, durum wheat and barley grown under well-watered (WW) and water-limited (WL) regimes in glasshouse conditions. The results showed that stem WSC content and the apparent mobilisation of WSC to the grain were much higher in triticale and were associated with its larger grain size and grain number. Grain weight and the number of kernels per spike were positively associated with stem WSC mobilization in the four cereals. Post-anthesis AA concentration in leaves was much lower than in the grain. Main AA components in barley grain significantly differed from those in grain of triticale, bread, and durum wheat. The water-limited regime reduced plant productivity in the four cereal species, but it had no clear effects on WSC content and AAs in leaves and grain. In general, triticale was less affected by WL than the other cereals. The finding will well-understand the physiological mechanism associated with source-sink regulation in response to terminal drought in cereal crops. Overall, this manuscript can be accepted for publication after addressing the following  comments/suggestions.

1. In Abstract part in Page 1: the first sentence, “Grain development in cereals depends on…and environmental conditions.”, is not enough accurate and need to be further revised.
2. Line 61 in Page 2, “There is evidence that…” should be corrected as “There is an evidence that…”.
3. Line 68 in Page 2, “…contents are considered useful traits for grain yield…” should be corrected as “…contents are considered as useful traits for grain yield…”
4. In the part of “2.1. Plant material and growing conditions” in Page 2, please supplement the methods of soil moisture control and detection for potted plants, because potted plants were supplied water and Hoagland solution under WW and WL conditions. How to control soil water content?
5. The experimental varieties as triticale, bread wheat, durum wheat and barley have same growth stage? If they are not, how to evaluate the differences in phenotypic traits of different crops based on fixed time of measurement, because the content of metabolites of WSCs, AAs and nitrogen is easily changed by the growth time.

Author Response

Thank you for your comments. We addressed all the comments and modifications to the manuscript are indicated in blue.

Author Response File: Author Response.pdf